ABS Light problem

[Aelfred]

I've not been able to find any other post which matches this problem so here goes.

I have a 1.3 Yaris 2004 registration (T3). When driving at speed the ABS light will come on when taking a shallow right hand bend (British Motorway driving). The local dealerership found the sensor involved was dirty and cleaned it giving it a thourough check. The problem has not gone away though. After trying again they reurned the car but the same thing happened again.

On the third visit, they downloaded all the flow charts and concluded it must be the ABS ECU. The cost would be £750 to replace it. However I'm not convinced for the following reasons and have stopped them proceeding with the repair.

This happens in the one specific instance described ... never at any other time. The first time it went in for this fault they did a visual check on the car but despite my pointing out a possible fault, they did not fix it. That fault is the steering wheel which is off centre by about 10 degrees. Now on an old car in my youth I would have just removed the wheel and recentred it but on today's modern cars that fault usually points to the tracking and/or wheel alignment being out.

Secondly, because it only happens in one specific circumstance my view is that the signal is being sent to the ECU by some condition that manifests itself under this circumstance and that the problem lies at the sensor end and maybe is connected to the wheel alignment.

I am not convinced therefore that the proposed repair to the ECU is necessary yet. I am going to have the tracking and alignment checked independantly and see whther that fixes the fault first.

My reason for posting though is to ask for any advice on this problem and whether anybody has experienced the same or very similar experience. I must also question Toyota's wisdom in not providing any method of checking the ECU and simply expecting the customer to shell out for the very expensive repair with no guarantee of success - I should point out that when removing the old ECU, it is usually damaged and there is therefore no way of proving whether it was operating correctly or not.

I look forward to your replies.