Engine Management system faulty in C5!

[begins]

Hi all,

I had my C5 (Year 2007) 2.0L Petrol EW10A Throttle Body cleaned today. The Throttle body was very dirty as I watched the mechanic cleaning. They then used an universal scanner to search for any fault code in the car. None was detected.

However, while driving home, the message “Engine Management System failure” suddenly appeared and the service light was kept on. Otherwise, the car drives perfectly normal to me.

What could be the problem? So worry for another expensive repair bill. Can I continue to drive the car now?

Any kind souls here can advise me on this?

Thank you very much.

Regards,

[begins]

Hi all,

Decided to bring the car out for a spin and realized that the both “Engine Management System Faulty” message and the Service light have gone off!

After cleaning the TB, the car seems more responsive now and I hope it will be alright from now (touch wood).

Regards,

[qprdude]

Error /fault codes can take several miles to clear Even a blown bulb message can remain on when a new one is fitted. Don't worry about it, just enjoy the new responsiveness.

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Error /fault codes can take several miles to clear Even a blown bulb message can remain on when a new one is fitted. Don't worry about it, just enjoy the new responsiveness.

Thank you very much for the consolation.

Oh dear, the “Engine Management System faulty” message appeared again after a continuous drive of 1 hour with max at 4K RPM. Again, it only appeared once the car has come to a complete stop. Anyway, I will not be using the car for the whole of next week as I’m currently out of town.

Hopefully, a week of rest will erase that irritating message...keeping my fingers crossed.

Regards,

[begins]

Hi all,

Just drove my car this evening after a few days away.

Like usual, the Engine Management System faulty and service light didn’t turn up when ignited.

However, after a long drive when I stopped at the traffic, the message and service light appeared again! So this has been the symptom, start ok, drive for a while, when come to a stop, message and service light will emerge.

This time round, when the message and service light surfaced, the car would vibrate (almost like asthma). Once I restart the engine, the car will stop vibrating but with the service light on.

Can the expert advise me what to look out for to solve this problem?

Thank you very much.

Regards,

[begins]

Hi all,

This is an update to the problem.

My car finally stalled when the “Engine Management System faulty” message popped up. It simply refused to move after several restart.

No choice, it was towed again (4th time within 8 months).

This time round, the starter fused has blown. It was replaced and I took the chance to change the battery to larger NS70.

Now no more error message and service light even when stopped at traffic after a long drive.

I hope this put an end to the problem.

Thank you all for reading.

Regards,

[CassC5]

Hi, begins.

I know I’m ten years late to the party but I’m experiencing the same problem.

I was hoping your issue was the same as mine and it look like it is.

So you got a new fuse, replaced the battery, and all was well? Where is the starter fuse located?

[wheeler]

You would be better of starting a new thread with your specific car, all we know at the moment is that its a C5 tourer. What year is it & what engine do you have for a start? The fuse locations are different depending on if its a mk1, 2 or 3. Are you having the exact same problems as above after cleaning the throttle body?

[asaf400]

Wow, that was scary, I had the exact same issue, EW10A (RFJ), Throttle body cleaned while battery was connected, upon starting the car I noticed that the brake pedal is stiff - no vacuum, after restarting the car I noticed the error message, my mechanic was shocked..

We disassembled the air filter and intake duct again, tried a few restarts, and BSI reset, also disconnect and reconnect the map sensor, the engine was still acting weird, rough idle, wrong rpm, some misfires too, and sometimes with the fault, the throttle pedal would literally be ignored by the ECU, and it would only rev up and down uncontrollably (1500), we tried clearing engine faults using OBD, as well as holding the 000 button below the dash screen while turning the ignition on..

The weird thing is I don't understand the relation to the brake vacuum, are the intake and brake booster connected??

Anyway, after letting this car seat with disconnected battery for a few minutes and intake filter fitted back and reenforce the existing connections
(Electrical and mechanical), we turned just the ignition and 'manually' calibrated the throttle, going from idle to full push including the kickdown button, a couple or so times, then Again now with the engine on, repeat that 3 times, and all problems are gone.

Brake has vacuum, and no engine fault or service message.
Engine is smoother then ever before, idle very stable, throttle response is lively..

What the actual (-expletive removed-)?
That was very frustrating to go through, is the engine management designed to default to mars atmosphere? The short term negative effects of cleaning are too outreaching, more then they should be..
the positive outcome makes me happy to have done it, but.. it was not expected