C20XE ECU code 55 (ECU failure)

[MarkGSi]

Anyone any ideas what this actually means? I've had this code come up a few times over the years but usually it's only when i start the car and it idles for ten minutes before i touch the accelerator. However today the light came on whilst i was driving and the car went into LOS. If i turn the ignition off and then back on the ECU light goes out as it should.

Many thanks
Mark

 

[turbojay]

i had this on my old c20let ecu, apparently it is what it says. . . a malfunction of the ecu, normally it happens when copied chips are used, i changed ecu and all is fine now

 

[MarkGSi]

Hi Jay, i've had the car 8 years and you could count on a buthers hand how many times its done this. I'll keep a look out for an ECU just incase it does start to get regular.

Cheers
Mark

 

[Rusty]

So the code is "ECU Failure" and you have to post here wondering what the problem could be?

Can't really argue when folks say the world is getting dumber

 

[MarkGSi]

So the code is "ECU Failure" and you have to post here wondering what the problem could be?

Can't really argue when folks say the world is getting dumber

I agree Rusty, does sound a bit daft but if the ECU has failed surely it wont keep going and the car would just sit down?. It had always been that if i started the car and left it idling without touched the ACC pedal, after a few minutes the Code 55 would come up. I just assumed it was having a bad day but on the recent occasion it did it during driving. Jay's response was useful to me so i'll be looking for a spare ECU just in case.

 

[scooby]

Has the ecu been chipped as some chips can cause this fault

 

[MarkGSi]

Has the ecu been chipped as some chips can cause this fault

No mate, as far as i know it's a standard ECU. Would i be able to see if the chip has been changed by looking inside the ECU? (or should i not open up a can of worms!?)

 

[turbojay]

its fine to open it mate, if it has been chipped they may look like blank black chips, best way is to take a pic for us

 

[MarkGSi]

its fine to open it mate, if it has been chipped they may look like blank black chips, best way is to take a pic for us

Will do this at some stage mate, many thanks

 

[Andy_Mk3]

This is what comes up on autodata, worth a try.

 

[MarkGSi]

Thanks Andy, this is useful stuff and has come at the right time. I've been wondering today if the ECU could get fooled by an equivalent of electrical noise? On the morning the light came on (when i was driving along) the car had been briefly mis-firing? Could very damp, very old and dodgy leads plus worn-out dizzy (cars are last on my agenda at the moment although i have the parts to put on!) cause the ECU to throw up the 55 code? I've read your post and i'll check out these connections to see if any problems (noise) is being created there.

Mark

 

[Mark T]

On the XE M2.5 ECU it comes up quite often when you've fitted the Courtenay Group N Chip.

Doesn't affect the running though.

 

[KinG^Lee]

I had this fault when my ecu was chipped, also had another fault on there due to a damaged cable going to my sensor, i fixed the sensor and for some reason the 55 code went as well.