406oc.co.uk

I have a 2001 406 2ltr estate, for last 2 days the engine light has stayed on, the car drives perfectly and starts fine.

I took it to a local auto car electrics guy who ran tests on the ECU managements system, he found no engine faults, he did find some air con flags that he managed to cancel, on a retest he then found no faults at all, but engine light still stayed on.

He then called his technical guy ( his cousin) who said that it was a common fault with the magnet marelli ECU's and if he sent it off to them, they would repair the ECU and then the engine light will then be out, the cost of the repair would be about £300

I said to him, "what if I just bought a new ECU" he replied "you cant just change an ECU as it is programed for my car only on the chassis number"

Do you think he is telling me porkies?

I have found a place on the net called ecutesting dot com that will send a new one/recon for my car for £180 which is far less than a repair he was quoting me.

What do you think I should do? any help would be much appreciated.

There will be nothing wrong with the ECU at all.

Moreover there will be a wiring fault to a sensor somewhere and even corrosion on the main ECU harness plug itself. None of us on here have ever had to replace an ECU and the one occasion I can remember someone replacing an ECU (just like you have been advised) then it didn't solve the problem.

I had the check engine light up on mine a few times (1999) and the first very difficult to find fault was the radiator fan which was replaced and after that I've had 3 throttle position sensor faults.

A lot depends on the quality of the diagnosic equipment here as the Peugeot ECU is 'secretive' about disclosing the root of the problem and many garages will go off down the wrong road to repairs

See what others say but don't do anything with the ECU just yet.

Oh yes, you'd better confirm if it's a petrol 2.0 or diesel but my opinion stays the same in either case

Hi welton, thanks for the reply, I will not change the ECU like you say, hope to hear from others on the subject.

so do you think it will be fine to keep driving the car? as it still drives fine and starts fine?

Hi,

I have a similar problem with my engine light coming on... If i just plod around town and keep the revs low it doesnt come on but if i hit a dual carriagway or equivalent and put my foot down a little it comes on within a minute. Once it comes on it then goes on and off for the entire journey. I thought the guy who owned it before me had put the incorrect grade of oil in so i gave it an oil change but hasnt helped. The car seems to run ok and its just passed the emissions on the MOT so im running out of ideas.

Minipug

Accelerator pot may be and area to check, these often give doggy signals (carbon track breakdown on the inside).