ECU shuts down engine after 5 seconds

[analogman]

Can anyone answer a couple of questions for me? I have a 1.3L automatic P reg. It suffered with missing a beat once or twice every few minutes. This would also happen when standing and idling, the engine would drop momentarily then recover immediately. After changing the plugs, distributor cap and rotor arm a web search indicated the Air Flow meter as prime cause. I replaced this to no avail. Also advised was to check corrosion on injector fuse. After a week of this the engine check light started flashing permanently and the engine starts, runs for exactly 5 seconds and cuts out. Repeatedly the same condition at every start up.

Checking the diagnostic connector mode 2 I get 14 long flashes followed by 1 short, then 14 long, 2 short and the cycle repeats. I finally put an oscilloscope on the injectors and can see the 12V at ignition dropping to zero with nice wide pulses. As the engine cuts (after 5 secs) the pulse width drops to a thin line. So the ECU is setting the injectors to close off fuel.

I have measured the fuel supply pressure at 2.5 bar, it is correct.

My questions are:

1) How does NATS inhibit engine, does it prevent the ECU from even starting the engine in the first place, or does it shut it off after a short time?

2) Does anyone recognise the above conditions and, if so, what was the cause.

3) Pretty much the last thing left is the ECU, but changing it presumably means reprogramming the keys NATS codes into it. Can this be done DIY?

Any helpful suggestions would be much appreciated. Thanks.

 

[ollyc98]

Ed is probs the best guy to ask about this but have you considered switching to a non-nats ecu? it'd save you having to get it recoded. Of course if it's an easy job then just get a nats one recoded.

 

[frank]

analogman

it sounds like a nats problem to me
i think there is a relay that turns on the fuel pump for 5 secs only, if the ignition is left on
i think you have to swop a couple of wires if you fit a non nats ecu (ref ollie 240585 iirc )
btw where are you based ?

 

[98twister]

It sounds similar to a problem i had on our 96 Micra.
I was getting 141 and 143 error. Not the 142.
It was caused by corrosion to the fuel pump fuse.

http://www.ilexa.co.uk/forum/index.php?topic=463.0

 

[Ed]

Sounds like nats to me.

 

[analogman]

I still have this problem and have mananged to get a cable and the "Consult" software for a proper diagnosis. It comes up with error codes E1 and E2, which, I guess, it the hexadecimal way of saying 14-1 and 14-2 with the flashes. So I am not much further. Are there any Nissan technicians out there that can point me in the right direction. The codes can be cleared with the software but return instantly the ignition key is turned (even before starting the engine).

 

[analogman]

As help to others I can now confirm that these codes (E1 & E2 or 1401 & 1402 with the flash counts) are the loss of key codes in the ECU. Man came out with reprogramming kit and re-coded them in less than 5 minutes. No pin codes needed. I can now get back to looking for the original fault!

 

[oikealle]

Nats version 2 has no nats code. Red chip key = no code Blue chip = nats code.
if your interested i can tell you the fault is the immu failing behind the glovebox.
If you want to bypass nats immu it can be done with some simple jiggery pokery, let me know if you want me to email you a wiring diagram guide on the bypass etc.
ps fault would poss be chain of immu key in nats self diag memory.
regards Ben

 

[oikealle]

forgot to mention, culprits on k11 ecm losing power is usually rotted EGI fuse in the engine bay, headlamps also rot. The nats lamp wouldnt flash though if this happened. Over the years , back even as far as 98 or 99 k11s were always being towed in for this problem. The nats system is simple it consists of something like this:-
Red chip key --- Antenna Amplifier--- Nats immu ---Engine ECM.
The antenna amp energises the chip sends the encrypted fixed signal to the immu (immobiliser control unit), if it likes the signal , i.e. if it matches the immu then sends a signal to the ecm to allow starting. i have a way of cutting out the immu of this loop therefore rendering the nats system dead. PM me for details as i wouldnt want to issue details for the world to see with it being a security concern.

 

[redthing]

Hi. I've been reading this thread because my sister in laws K11 is doing the exact thing. I also have a manual K11, which is why I joined this club. Would it be possible for you to send me the details on bypassing the NATS so that her car doesn't keep cutting out too.

 

[fob12]

dude can you hear the fuel pump priming at the back of the car when you switch on the ignition could be either nats or a relay for the fuel pump you should hear a click after the fuel pump has primed it should do this all the time not now and again.

 

[redthing]

Thanks for the reply. I'm in Southampton & my nephew is in Norfolk (where the car is) trying to fix it for his mum. I've passed on your suggestion but the fuel pump is apparently priming as it should. The car's not worth much so spending a lot of money fixing it is out of the question, so you never know, I might post back saying its for sale!!