See GenBoard/Manual/GroundConnections
Some symptoms usually (almost always) indicate ground problems in the harness, or some intermittent or broken connection
- if MAT or CLT changes when some outputs activate, or when engine runs, or some output is forced low (eg. ignout driving fuelpump relay is shorted to GND)
- if outputs work when engine is OFF, but not reliably when engine is running
- if all works OK at low power, but not at high engine power (when inj and ignition consume more, and overlap... the ECU is really fine with this, but if the voltage drop on some wires in the wiring is too high, it will cause problems)
- works with 1 ECU but not with another (can be several problems), or works sometimes, but not always
There are several indications that something with grounds is happening
- CLT reading: "When drived a bit and let run in idle i saw the Watertemp goes higher than usual..."
- this is from the original report (with no ECU serialnr).
- What does this mean, exactly ?
- Does CLT reading in VT change abruptly (just showing slightly higher water temp than real), when the fuelpump relay output is shorted to ground with a wire ?
- Or it somehow prevents fan turnon, and will slowly, eventually result in higher coolant temp and coolant actually gets warmer ?
- THIS IS VERY IMPORTANT to KNOW !
- how much higher ? +5C ??
- CLT: went higher than usual because the fan didn't start.
Pins and Ec Connectors already checked for gaps that could cause that. Nothing special seen.
And about the Vanos... its a ON/OFF vanos on the M52 head. That means its only full advance or retard. Nothing between it.
- So the output must work for that I mean ? (??)
- On the dyno it worked for sure.