Anyone know what I should be looking out for if this was faulty?
Trying to diagnose this problem: Stalling XE, I give up
if the sensor is truly goosed the engine wont run, period.If trouble code 19 was recognized (INCORRECT RPM SIGNAL), no replacement value is used for the engine speed signal. For the mixture and requirement adaption, current values are used and neutral values are used for idle control and characteristic curve adaption.
when mine went it was like the leads were on the wrong way round... lots of poping and flames when trying to bump start it lmao
no you cant !if the ecu recieves an incorrect rpm signal (that doesnt mean NO signal) it uses basic values stored in the ecu for fuelling, idle control and all learn functions.For the mixture and requirement adaption, current values are used and neutral values are used for idle control and characteristic curve adaption
obviously if it receives NO signal it wont run at all.
they can cause all sorts of daftness.
trouble restarting when the engines warm is what I had - it started from cold perfectly - once running it was ok again.
on the vectra the light used to come on 5 mins into a journey.
> will reading the fault codes off the ECU determine this reliably?
No, its not that cleaver.
At start up, the ECU does a quick scan of all its inputs and sees if it can see 12v, GND or high impedance inputs (ie is the sensor connected or not?).
When the engine is running it then can begin to look at voltages and frequencys and see if they are in tolerance. If its out of tolerance, then it will flag a fault. Hoever the sensor could be lieing or be lazy in its signal and the ECU will know no better. Or its an intermitant fault, ie less than 30 seconds and it won't log a fault.
also if the cam belt it lose it can give the same effect, it could be slake catching itself up (espically when you suddenly lift off the gas and then back on. The crank could be turning slighly different to that of the cams and the ECU may see this as an error. If the slackness is really big, then the timing is out big time and the valves will hit the pistons. So easy and free check, see what condiiton the cam belt is in.