Hi.
I have a unit that after a possible fault in wiring show strange symptoms. The voltage in VEMStune is about 9 volt, but I have 12 volt on the supply pin.
Also, one injector output, connected to fuel pump relay started to ground continuously on power on.
I have measured the transistor and there is no short, the transistor seems fine. The problem must be from the CPU?
- The injector FETs are driven by SOIC8 [FETdrivers] (TC4426 or MC33151D). The FETdriver is primary suspect in this case.
We did noting when a got a NEW unit that one ignition coil were cracked and the spark did exit just by the connector. It is possible the spark can have entered the signal wire to the IGBT
On this picture, by the pen, is that some form of 12v regulator/stabilizer?
- MC33269-DT5 (5V regulator in DPAK package)
- Could this be damaged?
- if 5V can be measured on it's output (big pad), than it's likely operational
Is there something I could check or is it better to send this unit in for service?
- The main +5V (and others, like on EC36/pin28) should be easy to verify
- also check that there are enough available non-damaged, operational FET and IGBT outputs.