Technical Stilo JTD - cambelt change, now no throttle

[Twincam1986]

I recently bought a stilo jtd (about 2 weeks ago) and took it to my usual local garage on thursday to get the cambelt and waterpump changed. I got a phone call from them to say that there had been a problem. They said the job went fine, they started it up afterwards and drove it round the block, then drove it back and left it to idle to make sure there were no airlocks in the system.

Then, when they went back to the car, the engine management light had come on and it would not respond to the throttle. Their diagnostics were unable to read it's ecu, so they had an auto-electrician come down who has said that the ecu has lost its feed from the throttle, and that basically it needs a new ecu. To try and save on costs, they are going to send it away to try and get it repaired, however these people don't go back to work until the 9th jan, so the car will be off the road for a good while.

They said that they do not know if it is just a coincidence that this happened or if it could have been them - they said they did have to move the ecu to do the job, but all they did was unplug it then plug it back in, and as said, it drove fine when 1st started after the procedure. So it's a bit of an awkward situation. They have been honest with me and he offered to lend me his van over xmas so that I would have something to get about in.

What I'd like to know is has anyone ever experienced this before and was it the ecu, or something else? Also, could this just be a coincidence or as a result of the ecu being moved - it's never done this in the time I've had it. Only fault was the airbag light was on. Any thoughts?

 

[Davren]

Hi, Welcome to the FF.

they had an auto-electrician come down who has said that the ecu has lost its feed from the throttle, and that basically it needs a new ecu.

The Stilo throttle is "fly by wire". The engine management ECU gets signals from two potentiometers mounted on the accelerator pedal. If the ECU has "lost its feed from the throttle", it's more likely to be a fault with the accelerator pedal than the ECU.

Also, could this just be a coincidence or as a result of the ecu being moved - it's never done this in the time I've had it. Only fault was the airbag light was on. Any thoughts?

Obviously a fault in any electronic component can manifest itself at any time so yes it could just be a coincidence.

The JTD ECU and it's connectors are fairly robust, but the problem could have been caused if any of the pins or sockets were damaged while reconnecting it. The wiring to the ECU is quite tight and the connectors need to be refitted at an angle which can be awkward.

I've removed and refitted the connectors from my JTD ECU several times without causing any problems.

 

[Steve148]

could this just be a coincidence or as a result of the ecu being moved

It's very unlikely that a solid-state, well-armoured ECU would coincidentally fail at this exact moment. Much more likely that it's been damaged by rough handling, a yanked connector or a momentary short circuit or something.

 

[buster]

I would agree with the above comments.In the time i owned my Stilo jtd i did the timing belt 3 times myself.I cant ever remember disconnecting or moving the EDC control unit although it is situated over on that side of the engine.
The throttle pedal consists as said of two petentiometers,one acts as an idle validation switch.
The throttle pedal does not feed the EDC control unit,but quite the oposite,The EDC supplies the pedal with a 5v feed constantly and expects to see a signal from the pedal rangeing between 1 to 4v.
I have quite a bit to do with Bosch EDC 15 on other vehicles,and it is a robust system,the only failures ive seen are through engine oil coming down the injector harness,but there is no way this could effect the stilo set up.
The wiring needs load testing with a 21watt bulb.It must surely have got damaged during the job.