Join Date: Mar 2017
Location: Surrey , England
Just to keep information up to date..... one reputable Indy advised me that the TRAC FAULT cannot be removed with a diagnostic kit and that it was an ECU problem and that I would have to remove the ECU and have it bench tested as it should have cleared when the sensor was replaced.
Another Indy ( I am lucky to have 2 very good shops equidistant from me - 45 mins ) told me to bring the car over, they plugged in the diagnostic kit in the glovebox plug and cleared the fault in about 2 minutes.
Very depressing to find that such a difference of diagnosis exists even amongst the 'experts'.
The post script is that as soon as the fault was cleared the traction cut out symptom started to kick in again at motorway speeds. However, the TRAC FAULT signal did not reappear and I am able to switch off the TRAC again from the centre console.
The shop that cleared the fault were adamant that they have seen the problem numerous times ( and they are Continental R, T etc specialists ) and that the cure is to replace the 2 front phonic wheels to ensure that a clear equal strength signal is coming from both front wheels. One new phonic wheel , they say, can still have an imbalance in signal and thus cause the traction control system to assume a problem has occurred.
I will set about that job now, which apparently entails removal of hubs, knocking out the 'pressed in' phonic wheel, replacement of bearing seals which will have been disturbed by the work, pressing in new phonic wheels and hopefully - hey presto - problem cured.
For those interested I will report back when the work is completed. For those not interested, I sincerely hope you do not experience this issue as it is awful when driving on motorways.
Motorman Thank you for quick reaction advice from first query. As an aside, is the diagnostic plug specific to Bentley or can we use other diagnostic kit on these cars ?