O C Diver
Guru
- Joined
- Dec 16, 2010
- Messages
- 13,317
- Location
- Fort Myers, Florida
- Vessel Name
- End Of The Line
- Vessel Make
- Trinka 10 Dinghy
The ECM is likely using a reference resistor that the CPU is doing a comparison against to the pump circuit. These reference resistors change resistance with temperature to some degree. If it's a very sensitive and low resistance change being measured, the increase in temperature of the ECM may be enough to affect the reference resistor value and trigger an alarm. Or, the reference resistor itself or soldering may be weakened due to heat cycling. Keeping the ECM cool is just a good idea all around so separating it from the engine and adding a heat sink or fan seems like a good plan.
Also, just wondering if there is a difference due to removing any grounding on the ECM by zip tying it away from the block. If it is now not grounded then perhaps this is due to a ground loop issue?
Just guesses...
Thanks! Much appreciated the knowledge on the reference resistor.
Regarding the ground:
The ECM wiring harness has it's own positive and negative power supply wires. It's required to be hooked directly to the battery to avoid low voltage to the ECM during engine cranking.
Ted