Had this problem a while back but seems to have made a reappearance.
Car only starts maybe 1 in every 10 attemps.
Turns over fine but won't fire.
Cam-position sensor, crank sensor and speed sensor all ok. (checked with scope when I get the engine to run)
Battery is relatively new, works fine in other car.
With vagcom attached.
1. Start condition - Key in ignition. Dash voltmeter reads 12v - Vagcom reads 12v. Turn key - Voltage dips slightly, engine turns over, starts and runs fine. Vagcom and in car gauge both read 13.5 v with engine running. Confirmed at alternator and battery with multimeter.
2. Non start condition - Key in ignition. Dash voltmeter reads 12v. Vagcom reads 12v.
Turn key - Voltage in dash dips slightly as before but reading on vagcom voltage drops to 1.5-2.5v. Engine still turns over as strongly as before but will not start.
Vagcom fault code -
00532 - Supply Voltage B+
27-10 - Implausible signal - Intermittent.
I guess above is pointing to ECU seeing low voltage with ignition switched on. Should I be looking at the ignition switch itself? Bad earth? I've previously checked the earths at Manifold and a-pillar but maybe need to recheck them. Where does the ECU get its voltage reading from? Must be different to where the dash voltmeter reading comes from?
Any pointers welcome. Mechanical problems I'm fine with but as I can't see electricity I consider it to be witchcraft... although I'm getting better and can at least now use a multimeter.
Car only starts maybe 1 in every 10 attemps.
Turns over fine but won't fire.
Cam-position sensor, crank sensor and speed sensor all ok. (checked with scope when I get the engine to run)
Battery is relatively new, works fine in other car.
With vagcom attached.
1. Start condition - Key in ignition. Dash voltmeter reads 12v - Vagcom reads 12v. Turn key - Voltage dips slightly, engine turns over, starts and runs fine. Vagcom and in car gauge both read 13.5 v with engine running. Confirmed at alternator and battery with multimeter.
2. Non start condition - Key in ignition. Dash voltmeter reads 12v. Vagcom reads 12v.
Turn key - Voltage in dash dips slightly as before but reading on vagcom voltage drops to 1.5-2.5v. Engine still turns over as strongly as before but will not start.
Vagcom fault code -
00532 - Supply Voltage B+
27-10 - Implausible signal - Intermittent.
I guess above is pointing to ECU seeing low voltage with ignition switched on. Should I be looking at the ignition switch itself? Bad earth? I've previously checked the earths at Manifold and a-pillar but maybe need to recheck them. Where does the ECU get its voltage reading from? Must be different to where the dash voltmeter reading comes from?
Any pointers welcome. Mechanical problems I'm fine with but as I can't see electricity I consider it to be witchcraft... although I'm getting better and can at least now use a multimeter.