Began as an intermittent fault where sometimes it would go into overdrive but now does not at all. So far I have changed gearbox sensor and also drained oil checked shift solenoids. First time I checked solenoids one was sticking so cleaned and appeared to work for a while. Once it failed again I ordered a solenoid from the states I'm in UK. Unfortunately it's a larger fit so jo good. But I checked the solenoids and all appear to be functioning. Any ideas appreciated. Cheers!
Could it be the thermostat? I know the cars wont engage overdrive unless the engine coolant is a specified level. For conventional auto boxes the engine temp must be at least 50c /122f and for ECT type auto the temp must be at least 70c / 158f. If temps are fluctuating or being read in error then this could cause the intermittent fault of OD coming on and off.
The sensor on the gearbox has been changed as this is the cheapest first option I will have to look into the temp thing though somehow.thanks for the input. Hopefully get it sorted.
So failed mot on emissions as wouldn't tick over. Checked the coolant sensor changed a while back and on the ohm meter seemed to be operating as it should. The engine did run better unplugged though. So as a new sensor was £9 I've fitted it and the result is one happy chappy! It has not only fixed the tick over the autobus now works normal in all gears! superb drives like new
