EPS Power steering column, what ACTUALLY goes wrong?

Hello Jason @huttojb . Thank you for all information you provided on this forum. I have no relation to mechanics and relatively new driver but understand that My Micra’s 2004 PS issue is not an easy fix in the garage :( Also engine light started to come up after ignition switch on. I am not able to PM you as only registered now. But will give you more details after be able to PM. We are in South West atm . Thank you for reading
 
Hi Jason. Are you able to help me please! So ive had the PS light come on the dash board, I took it to a garage who removed the fault codes, but day later the faults popped up again and only thing positive in this is ive developed big biceps. are you able to help mate? its 2004 plate? Automatic. cheers in advance
 

huttojb

Club Member
EPS System Guru
Hi Jason. Are you able to help me please! So ive had the PS light come on the dash board, I took it to a garage who removed the fault codes, but day later the faults popped up again and only thing positive in this is ive developed big biceps. are you able to help mate? its 2004 plate? Automatic. cheers in advance
No problem, you have already messaged me so will give you my mob number
 
Hi Jason. Same problem as others, PS light on and heavy steering on my 2006 K12. I need to replace the EPS'
If you could help me I would be very grateful. I am in Teesside so cannot bring the car down there. Is it possible for you to get me a unit and send it to me?
James
 

huttojb

Club Member
EPS System Guru
Hi Jason. Same problem as others, PS light on and heavy steering on my 2006 K12. I need to replace the EPS'
If you could help me I would be very grateful. I am in Teesside so cannot bring the car down there. Is it possible for you to get me a unit and send it to me?
James
Hey.
At the moment James I’m struggling to get any decent units, I have someone waiting for a unit and everyone I interrogate it has previous faults within its life history.

I’ll drop you a message and send you my number, I have someone who has 15 units and wants me to buy as bulk rather then a few, I didn’t need any yet and was planning to buy 10 late March for other applications, I may have to suck it up!

I’ll drop you my number

Jason
 
Well, thought I'd give a little update on mine.... 4.5 years since Jason worked his magic on mine and it's still going strong! (albeit, failed MOT on some unrelated areas, going to try to keep her on the road for another year)
 
Hey.
At the moment James I’m struggling to get any decent units, I have someone waiting for a unit and everyone I interrogate it has previous faults within its life history.

I’ll drop you a message and send you my number, I have someone who has 15 units and wants me to buy as bulk rather then a few, I didn’t need any yet and was planning to buy 10 late March for other applications, I may have to suck it up!

I’ll drop you my number

Jason
Hi Jason,
I have the same problem with a 2005 1.2 S Automatic. Did you manage to get any units?
 
Hey.
At the moment James I’m struggling to get any decent units, I have someone waiting for a unit and everyone I interrogate it has previous faults within its life history.

I’ll drop you a message and send you my number, I have someone who has 15 units and wants me to buy as bulk rather then a few, I didn’t need any yet and was planning to buy 10 late March for other applications, I may have to suck it up!

I’ll drop you my number

Jason
Jason, Can you send me your number so I can get in touch please?
Cheers
 

huttojb

Club Member
EPS System Guru
Well, thought I'd give a little update on mine.... 4.5 years since Jason worked his magic on mine and it's still going strong! (albeit, failed MOT on some unrelated areas, going to try to keep her on the road for another year)
Lol. That’s brilliant. Glad it’s still plodding along. 4.5 years. Well that’s a long time.
 
Hey all,

Now I am on my laptop I can reply properly.

I used to work at the manufactures of ther EPS System (TRW Automotive), where I worked in the Warranty Department analysising all UK and a percentage of international Warranty Returns to improve Manufacturing of the product. I also did some dealer visits and vehicle investigations in my time aswell.

So basically, I know everything there needs to know about the Nissan K12 EPS System.

You are correct, you cannot fit a second hand unit to a vehicle because the system handshakes with a dongle to the BCM and restricts ignition on if the dongle does not match. I know people who have fitted second hand units to their vehicle and it's worked, but not sure how they did this (I do have my opionions how you could possible do this but wouldn't want to broadcast on an open forum - becuase I am not total convinced and never tried it). I don't think TRW ever released the knowhow on clearing the dongle, when I visited Nissan Technical Centre to do some testing on a vehicle - not even Nissan had the ability to clear the dongle on the EPS System.

Next Subject, Fault Codes. The System has many internal fault codes which only display to a handful of DTC on the vehical. If the system identfies a failure it will generate a internal fault code and reduce the asssistance to 0% by disengaging the moter relay for safey. On ignition cycle the fault will be cleared unless it's a hard failure and the fault code will regenerate. If the fault code is generated 3 times in a row then the system latches and generates a System latch and can only be cleared by a diagnostics machine over CAN. These fault codes are Level A, Level B and Level C failures within the system. Level A Failures are normally CAN Issus (Communication Protacol), Level B are hardware failures and Level C are Latch Faults.

During the production there were known hardware and software issues within the system which was resolved during manufacturing. Earlier Systems are more common to fail then later systems. Software failure are normally intermittent and fails but when cleared would normally not fail again.

The system is designed in 3 blocks, ECU, Motor and Torque Sensor. The Motor was manufactured by Globe Motors and are very reliable apart from the Relay that is fitted. The Torque Sensor is an optical system produced in a clean room environment and the ECU was manufactured internally by a sister plant. I wouldn't recommend anyone trying to repair or opening the system without knowning what they are doing. I have questions a few of the re-manufacturing companies that state they repair the systems asking what exactly do they repair (just out of interest) but never got a reply. I would really question their intentions because I know TRW would never release the source Code or Database Files for any external site to repair the EPS. I was working in Prague for 1 year to estblish a Re-Manufacturing process for the EPS Systems and to be honest, it never hit off due to safety and the manufacturing plant didn't want to release the source code - it's agood job I had all what I needed! TRW always said that no system would ever be released if a Failure ever occured regardless of cause; I remember we had a production failure where the test machine was created internal fault codes into the system and all the systems were scrapped (over 200).

The system works on the CAN System of the vehicle and transmit and receives data to and from the ECM, BCM etc.. The system can be interigated with TRW mapped databases and internal parameters can be monitored and configurated over the CANbus. This was never released (as I'm aware) to the general public or Nissan.

Unforntunatly TRW lost the contract for the K12 system in 2009 (I think - if I remember correctly) which was unforntunaity becuase by 2006+ the system was really good and I would recommend the system to anyone. I beleive Delphi now produce the system for the K13 and also a retro fit for the K12 for the TRW replacement. I left TRW in 2010 and went on to bigger and better things.. but I do still know alot about the system and could really help someone if needed with reading the internal fault codes and resetting the dongle if required.

Another thing that I didn't talk about - The system has diffenrent Tune data for different Car configurations, without reading my old notes this was, Perol, Diesal, Sport and C+C Model Range. The system has boost curves, self steering centring and all the good stuff which can be configured with the right tools.

As someone said above, the system does have 2 relays, These are actually called a Link relay and Motor Relay. The Motor Relay is to activate the motor, and to disable the 3-phase motor on failure if required. The Link relay is on the ECU.

I'm trying to answer all the questions above with alittle of information, faults can be caued due to the relays but it's just as likely to be an internal hardware failure. a spec of dust in the torque sensor or a software issue. As I said previously, the system has many faults ( i think around 130ish) and these are assigned to about 5 DTCs so therefore the below DTC might have 100's of root causes. i.e DTC 5606 might be due to the Motor Relay, or the FET Drive for the Mototr the hall sensor which monitor the Motor or the motor feedback circuit. So basically could be either Motor or ECU Fault - in Warranty we barely looked at the DTC unless the system had no internal fault codes because it never helped!

DTC Number Description
5601 Battery Voltage Fault
D000 CAN Bus Fault
5609 CAN Vehicle Speed Fault
5611 CAN RearGearEngaged Invalid
5603 EPS Transient Fault
5604 EPS Operation Fault – Torque Sensor
5606 EPS Operation Fault – Motor
5607 EPS Operation Fault – NVM
5608 EPS Operation Fault – ECU
5604 EPS Internal Fault – Torque Sensor
5606 EPS Internal Fault – Motor
5607 EPS Internal Fault – NVM
5608 EPS Internal Fault – ECU

If someone needs specific details then private message me and I'll try and help.

The TRW System does get some negative feedback - but to be honest I like it. I like it that much I have fitted it to my kit car, this maybe because I can get it working and do some fancy stuff with it - but it's worked really well..

I think I have answered as much as I can - my wife is giving me that look to get off my laptop.

If I can post other helpful stuff I will.

P.S I live in Birmingham - UK so if anyone is around I'm sure I can help. I actually went to a scrap yard yesterday and got 2 EPS off a Micra for spares for my kit Car, knowing if it fails it easier to chnage it. Only takes 10 minutes to remove the EPS (from a scrap car) the bottom of the dash does get in the way and I break it on the scrap car!!!

Hope it made sense and everyone gets alittle information.

Jason

Hi,

This thread got now a couple of years, but I thought it would be worth a try.
I have bought a K12 Micra 1.2S recently and I have noticed an intermittent Power Steering problem at a start of the car. Turning on and off the ignition was clearing those initial problems. After about 4 events like this, the fault has turned into permanent. I would hope that it is some simple sensor error that could be cleared.

The car isn't worth much these days, but it will have to last me for some time. I live in Birmingham and it would be great to take a look at the problem with someone had similar issues before, so I can avoid expensive garage diagnostics. Please contact me if you could help.

Meanwhile, I am training my arms to become strong, similar to what other people described ;)

Kind regards,
Tomasz
 
Hello Jason @huttojb . My daughter have a 2004 Nissan Micra 1.2 80hp with this problem, red PS light and no power steering.
It looks like we need a new EPS, part number for this car is 48805-BC15B
We live in norway but maybe you can help us?

Tore
 
Hey all,

Now I am on my laptop I can reply properly.

I used to work at the manufactures of ther EPS System (TRW Automotive), where I worked in the Warranty Department analysising all UK and a percentage of international Warranty Returns to improve Manufacturing of the product. I also did some dealer visits and vehicle investigations in my time aswell.

So basically, I know everything there needs to know about the Nissan K12 EPS System.

You are correct, you cannot fit a second hand unit to a vehicle because the system handshakes with a dongle to the BCM and restricts ignition on if the dongle does not match. I know people who have fitted second hand units to their vehicle and it's worked, but not sure how they did this (I do have my opionions how you could possible do this but wouldn't want to broadcast on an open forum - becuase I am not total convinced and never tried it). I don't think TRW ever released the knowhow on clearing the dongle, when I visited Nissan Technical Centre to do some testing on a vehicle - not even Nissan had the ability to clear the dongle on the EPS System.

Next Subject, Fault Codes. The System has many internal fault codes which only display to a handful of DTC on the vehical. If the system identfies a failure it will generate a internal fault code and reduce the asssistance to 0% by disengaging the moter relay for safey. On ignition cycle the fault will be cleared unless it's a hard failure and the fault code will regenerate. If the fault code is generated 3 times in a row then the system latches and generates a System latch and can only be cleared by a diagnostics machine over CAN. These fault codes are Level A, Level B and Level C failures within the system. Level A Failures are normally CAN Issus (Communication Protacol), Level B are hardware failures and Level C are Latch Faults.

During the production there were known hardware and software issues within the system which was resolved during manufacturing. Earlier Systems are more common to fail then later systems. Software failure are normally intermittent and fails but when cleared would normally not fail again.

The system is designed in 3 blocks, ECU, Motor and Torque Sensor. The Motor was manufactured by Globe Motors and are very reliable apart from the Relay that is fitted. The Torque Sensor is an optical system produced in a clean room environment and the ECU was manufactured internally by a sister plant. I wouldn't recommend anyone trying to repair or opening the system without knowning what they are doing. I have questions a few of the re-manufacturing companies that state they repair the systems asking what exactly do they repair (just out of interest) but never got a reply. I would really question their intentions because I know TRW would never release the source Code or Database Files for any external site to repair the EPS. I was working in Prague for 1 year to estblish a Re-Manufacturing process for the EPS Systems and to be honest, it never hit off due to safety and the manufacturing plant didn't want to release the source code - it's agood job I had all what I needed! TRW always said that no system would ever be released if a Failure ever occured regardless of cause; I remember we had a production failure where the test machine was created internal fault codes into the system and all the systems were scrapped (over 200).

The system works on the CAN System of the vehicle and transmit and receives data to and from the ECM, BCM etc.. The system can be interigated with TRW mapped databases and internal parameters can be monitored and configurated over the CANbus. This was never released (as I'm aware) to the general public or Nissan.

Unforntunatly TRW lost the contract for the K12 system in 2009 (I think - if I remember correctly) which was unforntunaity becuase by 2006+ the system was really good and I would recommend the system to anyone. I beleive Delphi now produce the system for the K13 and also a retro fit for the K12 for the TRW replacement. I left TRW in 2010 and went on to bigger and better things.. but I do still know alot about the system and could really help someone if needed with reading the internal fault codes and resetting the dongle if required.

Another thing that I didn't talk about - The system has diffenrent Tune data for different Car configurations, without reading my old notes this was, Perol, Diesal, Sport and C+C Model Range. The system has boost curves, self steering centring and all the good stuff which can be configured with the right tools.

As someone said above, the system does have 2 relays, These are actually called a Link relay and Motor Relay. The Motor Relay is to activate the motor, and to disable the 3-phase motor on failure if required. The Link relay is on the ECU.

I'm trying to answer all the questions above with alittle of information, faults can be caued due to the relays but it's just as likely to be an internal hardware failure. a spec of dust in the torque sensor or a software issue. As I said previously, the system has many faults ( i think around 130ish) and these are assigned to about 5 DTCs so therefore the below DTC might have 100's of root causes. i.e DTC 5606 might be due to the Motor Relay, or the FET Drive for the Mototr the hall sensor which monitor the Motor or the motor feedback circuit. So basically could be either Motor or ECU Fault - in Warranty we barely looked at the DTC unless the system had no internal fault codes because it never helped!

DTC Number Description
5601 Battery Voltage Fault
D000 CAN Bus Fault
5609 CAN Vehicle Speed Fault
5611 CAN RearGearEngaged Invalid
5603 EPS Transient Fault
5604 EPS Operation Fault – Torque Sensor
5606 EPS Operation Fault – Motor
5607 EPS Operation Fault – NVM
5608 EPS Operation Fault – ECU
5604 EPS Internal Fault – Torque Sensor
5606 EPS Internal Fault – Motor
5607 EPS Internal Fault – NVM
5608 EPS Internal Fault – ECU

If someone needs specific details then private message me and I'll try and help.

The TRW System does get some negative feedback - but to be honest I like it. I like it that much I have fitted it to my kit car, this maybe because I can get it working and do some fancy stuff with it - but it's worked really well..

I think I have answered as much as I can - my wife is giving me that look to get off my laptop.

If I can post other helpful stuff I will.

P.S I live in Birmingham - UK so if anyone is around I'm sure I can help. I actually went to a scrap yard yesterday and got 2 EPS off a Micra for spares for my kit Car, knowing if it fails it easier to chnage it. Only takes 10 minutes to remove the EPS (from a scrap car) the bottom of the dash does get in the way and I break it on the scrap car!!!

Hope it made sense and everyone gets alittle information.

Jason
Hi Jason.
I have problems with my EPS
on 2005 K12 1.4
PS light on again no PS.
Reset with scanner works for a short time PS light back on .
Looks like i need to replace it can you help .
Thanks Alan
 
Hey.
I used to work with the Nissan EPS and can help if anyone is near Birmingham?
Jason.
Hi Could you advise or help my k12 power steering fault .
Steering stopped working PS light on
I cleared codes steering working for short time then the same thing happens all over again .Thanks
 
Hey all,

Now I am on my laptop I can reply properly.

I used to work at the manufactures of ther EPS System (TRW Automotive), where I worked in the Warranty Department analysising all UK and a percentage of international Warranty Returns to improve Manufacturing of the product. I also did some dealer visits and vehicle investigations in my time aswell.

So basically, I know everything there needs to know about the Nissan K12 EPS System.

You are correct, you cannot fit a second hand unit to a vehicle because the system handshakes with a dongle to the BCM and restricts ignition on if the dongle does not match. I know people who have fitted second hand units to their vehicle and it's worked, but not sure how they did this (I do have my opionions how you could possible do this but wouldn't want to broadcast on an open forum - becuase I am not total convinced and never tried it). I don't think TRW ever released the knowhow on clearing the dongle, when I visited Nissan Technical Centre to do some testing on a vehicle - not even Nissan had the ability to clear the dongle on the EPS System.

Next Subject, Fault Codes. The System has many internal fault codes which only display to a handful of DTC on the vehical. If the system identfies a failure it will generate a internal fault code and reduce the asssistance to 0% by disengaging the moter relay for safey. On ignition cycle the fault will be cleared unless it's a hard failure and the fault code will regenerate. If the fault code is generated 3 times in a row then the system latches and generates a System latch and can only be cleared by a diagnostics machine over CAN. These fault codes are Level A, Level B and Level C failures within the system. Level A Failures are normally CAN Issus (Communication Protacol), Level B are hardware failures and Level C are Latch Faults.

During the production there were known hardware and software issues within the system which was resolved during manufacturing. Earlier Systems are more common to fail then later systems. Software failure are normally intermittent and fails but when cleared would normally not fail again.

The system is designed in 3 blocks, ECU, Motor and Torque Sensor. The Motor was manufactured by Globe Motors and are very reliable apart from the Relay that is fitted. The Torque Sensor is an optical system produced in a clean room environment and the ECU was manufactured internally by a sister plant. I wouldn't recommend anyone trying to repair or opening the system without knowning what they are doing. I have questions a few of the re-manufacturing companies that state they repair the systems asking what exactly do they repair (just out of interest) but never got a reply. I would really question their intentions because I know TRW would never release the source Code or Database Files for any external site to repair the EPS. I was working in Prague for 1 year to estblish a Re-Manufacturing process for the EPS Systems and to be honest, it never hit off due to safety and the manufacturing plant didn't want to release the source code - it's agood job I had all what I needed! TRW always said that no system would ever be released if a Failure ever occured regardless of cause; I remember we had a production failure where the test machine was created internal fault codes into the system and all the systems were scrapped (over 200).

The system works on the CAN System of the vehicle and transmit and receives data to and from the ECM, BCM etc.. The system can be interigated with TRW mapped databases and internal parameters can be monitored and configurated over the CANbus. This was never released (as I'm aware) to the general public or Nissan.

Unforntunatly TRW lost the contract for the K12 system in 2009 (I think - if I remember correctly) which was unforntunaity becuase by 2006+ the system was really good and I would recommend the system to anyone. I beleive Delphi now produce the system for the K13 and also a retro fit for the K12 for the TRW replacement. I left TRW in 2010 and went on to bigger and better things.. but I do still know alot about the system and could really help someone if needed with reading the internal fault codes and resetting the dongle if required.

Another thing that I didn't talk about - The system has diffenrent Tune data for different Car configurations, without reading my old notes this was, Perol, Diesal, Sport and C+C Model Range. The system has boost curves, self steering centring and all the good stuff which can be configured with the right tools.

As someone said above, the system does have 2 relays, These are actually called a Link relay and Motor Relay. The Motor Relay is to activate the motor, and to disable the 3-phase motor on failure if required. The Link relay is on the ECU.

I'm trying to answer all the questions above with alittle of information, faults can be caued due to the relays but it's just as likely to be an internal hardware failure. a spec of dust in the torque sensor or a software issue. As I said previously, the system has many faults ( i think around 130ish) and these are assigned to about 5 DTCs so therefore the below DTC might have 100's of root causes. i.e DTC 5606 might be due to the Motor Relay, or the FET Drive for the Mototr the hall sensor which monitor the Motor or the motor feedback circuit. So basically could be either Motor or ECU Fault - in Warranty we barely looked at the DTC unless the system had no internal fault codes because it never helped!

DTC Number Description
5601 Battery Voltage Fault
D000 CAN Bus Fault
5609 CAN Vehicle Speed Fault
5611 CAN RearGearEngaged Invalid
5603 EPS Transient Fault
5604 EPS Operation Fault – Torque Sensor
5606 EPS Operation Fault – Motor
5607 EPS Operation Fault – NVM
5608 EPS Operation Fault – ECU
5604 EPS Internal Fault – Torque Sensor
5606 EPS Internal Fault – Motor
5607 EPS Internal Fault – NVM
5608 EPS Internal Fault – ECU

If someone needs specific details then private message me and I'll try and help.

The TRW System does get some negative feedback - but to be honest I like it. I like it that much I have fitted it to my kit car, this maybe because I can get it working and do some fancy stuff with it - but it's worked really well..

I think I have answered as much as I can - my wife is giving me that look to get off my laptop.

If I can post other helpful stuff I will.

P.S I live in Birmingham - UK so if anyone is around I'm sure I can help. I actually went to a scrap yard yesterday and got 2 EPS off a Micra for spares for my kit Car, knowing if it fails it easier to chnage it. Only takes 10 minutes to remove the EPS (from a scrap car) the bottom of the dash does get in the way and I break it on the scrap car!!!

Hope it made sense and everyone gets alittle information.

Jason
Hi Jason ,I know the micra eps issues are on going a long time and you have helped many with your advice I am a mobile mechanic ,one of my elderly customers has power steering loss on her k12 micra 03 reg ,fault codes displayed c1604 and c1608 the Trw part number is 50410263 I got a second hand unit with same part number before I learned about the programming issues I would be very grateful for any advice .Thank you. Gerry.
 
Good evening. I’ll ping you my mobile number.
Hey Jason. How much would it cost to have the steering pump replaced. A local mechanic is asking for 150 + 50 for labour so just curious if it's a good price. I'm a couple hours away from Birmingham but wouldn't mind the drive if you can do it cheaper and have the necessary parts (I'm terrible at mechanics so have no clue what's needed)
 
[Nissan Micra 2005 K12 1.24 L 46kw petrol]
Power steering sometimes stops working, red PS indicator on. Fault codes C1606 & C1608. A diod on the control unit broken?

Hi guys! My mothers K12 has the dreaded PS not working issue. The problem was manifesting intermittently for some time, a reset of the code helped for some time. Now we asked a mechanic to check on battery and battery charging system, both seemed to be fine. Mechanic pulled the whole servo column out. We were told, that there is a hole on a diode on the control unit (see pictures).

We are from Czech Republic. I called couple of ecu repair companies, but most of them told me, that they don't repair this PS unit for K12 anymore, since it is likely that it will fail again right away and therefore they cannot guarantee anything. New unit from Nissan was quoted for about 1000 EUR. That is half of the price of the car, we cannot afford that. One company told us they can try to repair the unit for 500 EUR, but if it fails again afterwards, they will not provide guarantee.

What would you guys do? Is there a way how to save this car without expensive bill? We are really desperate. My mother is quite dependent on the car. She is an old lady and without PS she wont be able to drive.
 

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Sheets,

Like I said above, I wouldn’t recommended the solution suggested above. A used unit cost £40+ from a scrap yard but it will not be paired with your car and therefore you’ll have NATS issues. It is quite simple to remove and replace the EPS but you need to get it paired.

Not sure what the refurbish ones are like and don’t really trust them.

Would you be interested in sending me your one (at your cost), I’ll check it and either send the original one back with it cleared or send one from the scrap yard which can pair to your car if the original one Has a hard fault.

Message me and we can discuss.

Jason.
Good luck. May last for a few months. The torque sensor is an optical sensor and was manufactured in a clean room environment. And if my memory is correct, if there is any dust greater the 40 microns it can cause a failure. But if the dust moves it will then work once the faults are cleared. There is only a small window of operation so as long as the contamination particles don’t pass over the operation window it won’t trip again.

Obviously with the DTC code doesn’t give you exactly the internal fault codes, so there was about 20 internal fault codes relate to the torque sensor, from dust in the system to the disc falling off. 95% of the time it was contamination.
I do have 3 units in but hopefully you will be fine. I would replace the systems personally, especially on a torque sensor issue that can happen on speed. I did some testing with fault insertion on the MIcra and it’s not nice when the system trips at any kind of speed.

Usually people wait till it’s a hard fault, so you know where I am if you need me.

Jason.
Hi Jason,

I need some assistance with me EPS, any chance you can call me on O7821 167354

Thank you
 
@huttojb
Hi, like everyone having PS failure with a K12 Micra.
Was intermittent for a while but seems permanent now.
Was planning on trying clearing codes / reprogramming NVM but bad idea it seems.
Could you pm me ? Thanks
 
Hey all,

Now I am on my laptop I can reply properly.

I used to work at the manufactures of ther EPS System (TRW Automotive), where I worked in the Warranty Department analysising all UK and a percentage of international Warranty Returns to improve Manufacturing of the product. I also did some dealer visits and vehicle investigations in my time aswell.

So basically, I know everything there needs to know about the Nissan K12 EPS System.

You are correct, you cannot fit a second hand unit to a vehicle because the system handshakes with a dongle to the BCM and restricts ignition on if the dongle does not match. I know people who have fitted second hand units to their vehicle and it's worked, but not sure how they did this (I do have my opionions how you could possible do this but wouldn't want to broadcast on an open forum - becuase I am not total convinced and never tried it). I don't think TRW ever released the knowhow on clearing the dongle, when I visited Nissan Technical Centre to do some testing on a vehicle - not even Nissan had the ability to clear the dongle on the EPS System.

Next Subject, Fault Codes. The System has many internal fault codes which only display to a handful of DTC on the vehical. If the system identfies a failure it will generate a internal fault code and reduce the asssistance to 0% by disengaging the moter relay for safey. On ignition cycle the fault will be cleared unless it's a hard failure and the fault code will regenerate. If the fault code is generated 3 times in a row then the system latches and generates a System latch and can only be cleared by a diagnostics machine over CAN. These fault codes are Level A, Level B and Level C failures within the system. Level A Failures are normally CAN Issus (Communication Protacol), Level B are hardware failures and Level C are Latch Faults.

During the production there were known hardware and software issues within the system which was resolved during manufacturing. Earlier Systems are more common to fail then later systems. Software failure are normally intermittent and fails but when cleared would normally not fail again.

The system is designed in 3 blocks, ECU, Motor and Torque Sensor. The Motor was manufactured by Globe Motors and are very reliable apart from the Relay that is fitted. The Torque Sensor is an optical system produced in a clean room environment and the ECU was manufactured internally by a sister plant. I wouldn't recommend anyone trying to repair or opening the system without knowning what they are doing. I have questions a few of the re-manufacturing companies that state they repair the systems asking what exactly do they repair (just out of interest) but never got a reply. I would really question their intentions because I know TRW would never release the source Code or Database Files for any external site to repair the EPS. I was working in Prague for 1 year to estblish a Re-Manufacturing process for the EPS Systems and to be honest, it never hit off due to safety and the manufacturing plant didn't want to release the source code - it's agood job I had all what I needed! TRW always said that no system would ever be released if a Failure ever occured regardless of cause; I remember we had a production failure where the test machine was created internal fault codes into the system and all the systems were scrapped (over 200).

The system works on the CAN System of the vehicle and transmit and receives data to and from the ECM, BCM etc.. The system can be interigated with TRW mapped databases and internal parameters can be monitored and configurated over the CANbus. This was never released (as I'm aware) to the general public or Nissan.

Unforntunatly TRW lost the contract for the K12 system in 2009 (I think - if I remember correctly) which was unforntunaity becuase by 2006+ the system was really good and I would recommend the system to anyone. I beleive Delphi now produce the system for the K13 and also a retro fit for the K12 for the TRW replacement. I left TRW in 2010 and went on to bigger and better things.. but I do still know alot about the system and could really help someone if needed with reading the internal fault codes and resetting the dongle if required.

Another thing that I didn't talk about - The system has diffenrent Tune data for different Car configurations, without reading my old notes this was, Perol, Diesal, Sport and C+C Model Range. The system has boost curves, self steering centring and all the good stuff which can be configured with the right tools.

As someone said above, the system does have 2 relays, These are actually called a Link relay and Motor Relay. The Motor Relay is to activate the motor, and to disable the 3-phase motor on failure if required. The Link relay is on the ECU.

I'm trying to answer all the questions above with alittle of information, faults can be caued due to the relays but it's just as likely to be an internal hardware failure. a spec of dust in the torque sensor or a software issue. As I said previously, the system has many faults ( i think around 130ish) and these are assigned to about 5 DTCs so therefore the below DTC might have 100's of root causes. i.e DTC 5606 might be due to the Motor Relay, or the FET Drive for the Mototr the hall sensor which monitor the Motor or the motor feedback circuit. So basically could be either Motor or ECU Fault - in Warranty we barely looked at the DTC unless the system had no internal fault codes because it never helped!

DTC Number Description
5601 Battery Voltage Fault
D000 CAN Bus Fault
5609 CAN Vehicle Speed Fault
5611 CAN RearGearEngaged Invalid
5603 EPS Transient Fault
5604 EPS Operation Fault – Torque Sensor
5606 EPS Operation Fault – Motor
5607 EPS Operation Fault – NVM
5608 EPS Operation Fault – ECU
5604 EPS Internal Fault – Torque Sensor
5606 EPS Internal Fault – Motor
5607 EPS Internal Fault – NVM
5608 EPS Internal Fault – ECU

If someone needs specific details then private message me and I'll try and help.

The TRW System does get some negative feedback - but to be honest I like it. I like it that much I have fitted it to my kit car, this maybe because I can get it working and do some fancy stuff with it - but it's worked really well..

I think I have answered as much as I can - my wife is giving me that look to get off my laptop.

If I can post other helpful stuff I will.

P.S I live in Birmingham - UK so if anyone is around I'm sure I can help. I actually went to a scrap yard yesterday and got 2 EPS off a Micra for spares for my kit Car, knowing if it fails it easier to chnage it. Only takes 10 minutes to remove the EPS (from a scrap car) the bottom of the dash does get in the way and I break it on the scrap car!!!

Hope it made sense and everyone gets alittle information.

Jason
Hi Jason, my daughter is at Warwick Uni and her PS on her 2006 Micra has failed. I moved away from Brum many years ago and unfortunately can't help as I'd like to. I'm happy to give you my mobile: 07906900493 is there anyway you could help as I'm getting so much confusing aspects to this that I don't know how to help assist my daughter. She simply can't afford to go to Nissan dealers! I'm sure she would be more than willing to meet up if that suits and are able to help her. I would be in your debt. Many thanks, Paul
 
I've just had an EPS failure on a 2006 K12 Auto fixed by a Nissan dealer. They put it down to having a 'non-genuine battery' which they replaced with one 'of the correct size'. I note from an earlier post that 'battery voltage fault' is one of the fault modes for this problem. Does the dealer's diagnosis make any sense to you all? It seems strange to me because it was the third non-Nissan-original battery that I've had in this car (all supplied by the RAC) and had never given trouble before.
 
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Hi Jason, @huttojb

It seems like you are the man to help, I’ve been trying to help a friend with her micra. The power steering failed, we pulled the motor assembly, had it refurbished, refitted and all seemed good, although the security light used to come on after a few miles, but it never caused an issue.

Now 4 months later it seems to have totally failed again. I wondered if you might have some insight into this?

Thanks

Max
 

huttojb

Club Member
EPS System Guru
Hey Max. The amount of people that contact me after using a reman unit is surprising!

Usually Reman companies just do a shot gun approach and change major components not really knowing the fault. You basically purchased a unit that failed previously and they’d probably cleared the fault and changed a relay or 2. If I remember correctly there were over 800 failures modes so how the hell would they know.

In OEM we could see the internal fault code which there was about 200, which helped us to analyse the failure mode, the only fault code the reman company could see is the DTC, if that… and there’s only 5 of them related to the EPS.

The Security feature was never released so doesn’t surprise me if the reman firm have no idea!

Where you located, anywhere near Birmingham?

Jason.
 
Hey Max. The amount of people that contact me after using a reman unit is surprising!

Usually Reman companies just do a shot gun approach and change major components not really knowing the fault. You basically purchased a unit that failed previously and they’d probably cleared the fault and changed a relay or 2. If I remember correctly there were over 800 failures modes so how the hell would they know.

In OEM we could see the internal fault code which there was about 200, which helped us to analyse the failure mode, the only fault code the reman company could see is the DTC, if that… and there’s only 5 of them related to the EPS.

The Security feature was never released so doesn’t surprise me if the reman firm have no idea!

Where you located, anywhere near Birmingham?

Jason.
Thanks for your reply Jason, I’m Bromsgrove, so not far from Birmingham but the car is in London. How much of it would you need?
 

huttojb

Club Member
EPS System Guru
Usually the unit is very self contained and usually when the ps light is on, it's a failure with the unit. Little fiddly to replace but not hard. Depends how attached you are with the car? I can check the current one and see if it is definitely the eps but if it is, I would recommend a replacement to a unit that has never had a failure since manufacture as this gives you the best possible chance not to get a secondary failure. But that's totally up to you as the car maybe beyond economical repair now days!
 
Hi all

Many years since I posted on the forum but wanted to sing Jason's praises for sorting out my NATS light today; my K12 had recently been fitted with a replacement EPS and it hadn't been set up properly - hence the often reported NATS light on after a few miles syndrome! Anyway, within a few minutes Jason had it all sorted and did the centering calibration for me too!

Worryingly, he also reported that the unit that has been fitted has thrown fault codes recently :-( So I'm driving round with fingers crossed! But a big thanks and thumbs up to Jason from me.
 
Hi there @huttojb, I am having a similar issue with my 2005 Micra. After resetting the fault a few times to restore the power steering, the engine light has appeared (despite the PS still working). I'd like to get it fixed. Please drop me your details if you can.

Thank you
 

huttojb

Club Member
EPS System Guru
Hi there @huttojb, I am having a similar issue with my 2005 Micra. After resetting the fault a few times to restore the power steering, the engine light has appeared (despite the PS still working). I'd like to get it fixed. Please drop me your details if you can.

Thank you
Hey Gman, engine light or NATS light?
 
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