EPS Power steering column, what ACTUALLY goes wrong?

Hi huttojb, if I can ask, in your experience when the column is faulty do you always get the eps light on, whatever the issue? I am down to two final options now on this k12 1.5dci. Column or ecu. Eps light going out with ignition on and never had any steering faults. After 2 auto electricians looked at this car I am wondering if one has entered the wrong pin number and locked the ecu out. On the third bcm now. Active keys are recognised and immobiliser light goes off. Comes down to the eps light question before the ecu goes off for checking and get it modified to remove the immobiliser side of things. Good job there isn't any pressure to get it sorted. Cheers.
 

huttojb

Club Member
EPS System Guru
Hi Just wondering if you may be able to help me out, I'm based in Bristol and have had the same intermittent PS problem ( on my 2003 Nissan Micra) everyone seems to have, however a few weeks ago there seemed to be an immobiliser fault and the ignition stopped working. It then started working again and after a local auto electrical garage cleared the codes, it worked for about a day and then same thing happened. It's now able to drive but with the PS fault. Not sure what to do as they said it would cost over £1000 to replace and not sure it's worth doing that over getting another car. Any advice would be much appreciated!
Where are you located, sure I can help.
 
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,

I have same PS issue with my Nissan Micra (K12), it happen about a year and a half ago but went away when I had the fault codes cleared at a local garage. The PS light has recently come back on (and the PS off) and a different garage has said that it has intermittent failure, is lightly to continue coming back and has suggested that I have a second hand unit fitted but from what I've read here that doesn't sound like a good idea.

I'm just south of Birmingham, do you have any advice on how to get this fixed?

Many thanks,

Liz
 

huttojb

Club Member
EPS System Guru
Depends how att
Hi,

I have same PS issue with my Nissan Micra (K12), it happen about a year and a half ago but went away when I had the fault codes cleared at a local garage. The PS light has recently come back on (and the PS off) and a different garage has said that it has intermittent failure, is lightly to continue coming back and has suggested that I have a second hand unit fitted but from what I've read here that doesn't sound like a good idea.

I'm just south of Birmingham, do you have any advice on how to get this fixed?

Many thanks,

Liz
Depends how attached to the car you are. Getting less and less cost effective to change the eps unit. But dropped you a pm anyway, can always help.
 
Step daughter has her driving test on the 22nd and the ps light is on and she's going to use the car for her test, its been reset a couple of times and so she really needs it fixed rather than reset.
Any ideas how to resolve ASAP as she's in panic mode.
 

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 but that's totally up to you. ?
 
Thanks for the quick response, The car is in very good condition and well worth keeping it just depends on the cost of replacing the dodgy part
 
Hi Huttojb, Same problem again with a Nissan K12 2005 plate. Problem has been intermittent (3 months) but could be reset through an OBD2 dongle (C1606). Now it seems to happen every day.
 

huttojb

Club Member
EPS System Guru
Hi Huttojb, Same problem again with a Nissan K12 2005 plate. Problem has been intermittent (3 months) but could be reset through an OBD2 dongle (C1606). Now it seems to happen every day.
Hey Ruffian. Yeah, usually intermittent faults turn into hard failures. Clearing fault codes through an OBD does not fix the fault.
 

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 but that's totally up to you. ? Dropped you a pm
 
Hi Jason, my micra eps has failed if you can help please let me know, text me if you can help on [removed] and I will call you. Thankyou
 
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huttojb

Club Member
EPS System Guru
Hi Jason, my micra eps has failed if you can help please let me know, text me if you can help on [removed] and I will call you. Thankyou
Dropped you a text but I’d edit the post and remove your number if I was you!
 
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Hi im so sorry if im doing this wrong. First time on here and have been trying to see how i can message you jason.
I was wondering if you could help.
I brought a 06 micra c+c in May and 2 months down the line the esp light and power steering light came on, ive taken it to a few garages but there unable to help. The last garage i took it to told me to have a look on here for you as you might be able to help.
Any help is muchly appreciated.
And im sorry for whos post this is that ive jumped on 🤭 @huttojb
 
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Yeah, I’m actually your side. M42 j2. I can have a look if you want.
That would be good if you could for me at some point?
Looking at previous posts on here, I'm sure you've fixed the same issue I have for others.
Thank you taking the time to reply.
 
Hi @huttojb,

I read through almost the whole forum and you said that LHD Cars can be hot swapped?

Could you advise me what to do in my situation? I have a Micra K12 2004 with faults c1604 and 1608 its a left hand drive (the netherlands) there is nothing for sale here (new) only second hand from the junkyard.

But I am a bit freaked out about the coding part, but if I am correct there is no coding needed for LHD cars? The car does have NATS and EPS which I can read with my diagnostics tool.
(the car just has a regular key no keyless entry or something)

I would really appreciate your help
 
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Looks like my wife’s micra is joining the list!!

@huttojb Jason, having read through this thread with interest I’d be grateful for your thoughts. My wife’s micra is an 05 urbis with about 20k. Her mum bought it new and gave it to my wife when she stopped driving so my wife’s very attached to it. The steering went really stiff a few days ago but no ps light, it then sounds like a relay clicking in and it starts working. Today for the first time I had the ps light on, I scanned it with Carista and got a fault code which I cleared and it’s been ok today- does this sound like the ps unit on the way out and if so where’s the best place to get one from, do you sell them. I took a couple of photos from underneath not sure if they help. I watched a utube video on how to change one which I’m sure I can do but would like to be certain the one I’m going to fit will cure the problem- many thanks in advance
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Hi
Hey jimc91. Where are you located, sure I can check. I’ll send you a pm with my mobile
I’ll drop you a pm with my number.
Hi there Jason, I'm another person jumping on someone else's thread with a ps issue! Looking at the number of issues resolved here you're gonna get a lot of Xmas cards this year ;-) Could I ask you to look at my wife's car please; it's a 2006 c+c & we have codes C1606 & C1608. We cleared them, it's been ok for a couple of days, but then came back 🙄 Many thanks Mark
 
Are there one who can help me with mt EPS on a nissa micra 1.2 2005.the steering is very tied to turn but no lights came one and no other problems..took it to lical garage and the quote me £200 - £300 ..bought the car only for £500 ..can anyone help me in that matter...im near birmingham UK..
TEL 07752899396
 
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