Sudden parking brake fault , gearbox fault, ESP and ASR fault all immediately after having an MOT done.

[Nicko1974]

Hi all, I sure hope someone can shed a ray of light here.
I took my C4GP for its mot today, it failed on on a couple of little things no water for washer jets on windscreen, a low brake pad and the emissions are high.
Any way I went to drive it home again and as soon as I pulled out onto the road the dashboard started lighting up like flipping Christmas!! On top of that the gearbox now won’t work on auto and only selects 1,2 and 3 on paddle shift, I rang them up and got a bit upset. I tried disconnecting the battery for 10 minutes to see if it would reset.
No luck
They then suggested they do a diagnostic on it but would have to charge me.
I disagreed with this as the problems where not there when I handed it them to mot,
They eventually agreed to have a look to see what the problem is.
They came back with a fault on the abs wheel speed sensor, so I convinced them to put it back on the ramp to see if the wiring had been dislodged whilst being tested. All seemed ok on a visual, and he deleted the fault code, but it would be straight back
as soon as I drove it off again.
Any way, I bought a new sensor for it, fitted it and the bloody problem is still there !!! GRRRR.
It’s been a great car and done us proud for the last 8 years. It’s a 59 plate 1.6 diesel and it’s now done 92k.
Anybody,, please anything!?!?!
Kind regards, nick

[RichardW]

Welcome!

You didn't have anything else done, like a new wheel bearing, while it was there did you? Does the warning come on at key on, or only when you drive it a bit? You will really need to get some more diagnostics on it - preferably with Diagbox / Lexia - to see what is going on. There was someone on here a few months ago had a broken wire to a speed sensor on one of these.

[Nicko1974]

Hi Richard. Thanks for your response. I hadn’t had anything else done to it, just an mot. I had no lights on before otherwise I wouldn’t have put it in for a mot as I know that would be a failure. Once the fault is cleared, the lights stay off until you drive it over 6 or 7 mph. Once the fault lights come on the auto box option stops manual only goes up to 3rd. and the lights stay on esp, asr, hill assist parking brake don’t engage.
Did the other guy have the same symptoms? Thanks again

[Gibbo2286]

Problems like this can often happen at MOT time, the car is subjected to treatment that it doesn't normally have to endure, high revving for emissions tests and heavy braking for the brake test, jacking up high so the wheels hang for suspension testing, all obligatory on the tester so it's not his fault if they shake out hidden faults.

[wheeler]

Have they tried reading & clearing the fault codes in all of the systems above?
Was the ABS fault code for more than one sensor? what was the exact wording of the fault code(s)?
Some time a rolling road brake tester can throw up a fault code with ABS sensors as it sees the wheels turning on one axle but not the other & thinks its a fault.
Normally it would show faults with more than one sensor and some time you also need to go in & clear the fault codes in all the related systems, parking brake, gearbox etc.
Apart from that unless there is any physical damage to the sensor wiring or connector I can think that they could have done anything wrong, as no parts should have been removed if it was just an MOT.

[GiveMeABreak]

As the ABS / ESP ECU is closely linked to the Gearbox ECU, any fault in the ABS system will often result in the gearbox going into a backup mode and typically it will be limited to third and display 'D3'. Ditto for the Handbrake, as the electric handbrake is ECU is controlled directly by the ESP system ECU under normal conditions. Functions such as Hill Start Assist will only operate when the original ESP / ABS system fault is fixed. So I would focus directly on the wheel sensors to start with.

[RichardW]

If the light goes out when you start it, but then comes on when you move, it passes the initial resistance test, so the wiring is probably OK. Once rolling it is either seeing an excessive speed from one (or more) wheel; or no speed at all. You really some live diagnostic data to see what's going on. Note, also on these engines, in a genius bit of programming, a fault with the EGR valve puts the handbrake / ESP light on, but NOT the engine light (go figure....!), so I would check that the EGR is behaving as well (it's possible that the full engine speed run has put the EGR in a position it is not used to, and it has jammed). I am surprised it failed on emissions, all these are DPF, so should be clean....???

[Nicko1974]

Hi all thanks for all your responses to this headache . I’ve also noticed that there is quite a bad leak (puff puff puff) from one of the injectors, ( might be throwing out the emissions test) so I’ve changed the copper se on that and that seems better. I think Richard may be onto something with the egr valve possibly sticking. As I’ve changed the speed sensor that the diagnostic flagged up and it sorted nothing. I did a diagnostics check on the parking brake and it showed no faults and also did some live data which still showed that the nsf wheel speed sensor is still not talking to the car. Could an egr valve prob really send me down completely the wrong garden path?! Extremely frustrated but still breathing

[Nicko1974]

Ahh, it turns out after I reinspected the new wheel speed sensor, it wasn’t seating perfectly due to a load of rust that had built up behind the old one. As soon as I chipped it all out, refitted the sensor, all the lights went out!! Happy days are here again. Thanks everyone who posted on this site. Wealth of knowledge between all you guys!

[GiveMeABreak]

Well done, always worth double checking, and thanks for letting us know the outcome.

[Hell Razor5543]

Well done, and good news.