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 like this
- 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).