Ambiguous engine warning light, symptoms are:
- Drives fine from cold start, to (for instance) local shops where it is parked
- Return to the car, which is then warm started
- Engine warning light appears and remains on, especially when the car is reversed out of a parking space
- Sometimes, as per the above, if the air-con is on and reversing from a parking space, the vehicle will stall and the engine warning light will appear (this has also occurred on a cold start)
- Pulling over immediately and shutting off the engine for 15-30sec and restarting results in engine warning light staying off for the subsequent journey
- No other symptoms, vehicle seems to run fine with no other (known) problems
Although the car has seen a considerable mileage, the engine has had considerable work done over the last 12 months; incl: replacement ECU, repalced cam belt with belt timing, water pump replaced, most seals replaced, oil filter replaced and more. Alternator not touched. Cigarette lighter plug voltage tester shows consistent voltage generally from 13.4v to 14.1v while the vehicle's in operation, unless air-con is engaged, at which point readings as low as 13.0v can be obtained.
The problem is so intermittent that there is no guarantee that the vehicle will reproduce the issue at service. Rather, the service tech would need to be on site when the problem appears, which is no real help given the nature of the problem. So. It's rather hard to get the car and a OBDII unit together at the right time.
Just want to know whether there's any ideas of where I should start looking for issues that may be causing this set of symptoms.