Operation CHARM: Car repair manuals for everyone.

Resistance Check

ECM and its circuits can be checked at ECM wiring couplers by measuring voltage and resistance.

CAUTION:
- ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM with coupler disconnected from it.
- Disconnect ECM couplers from ECM with ignition switch OFF.
- Never touch terminals of ECM itself or connect voltmeter or ohmmeter.





- Check resistance between each terminal of couplers disconnected.

CAUTION:
- Be sure to connect ohmmeter probe from wire harness side of coupler.
- Be sure to turn OFF ignition switch for this check.





ECM TERMINALS RESISTANCE
- Resistance in table above represents that when parts temperature is 20°C (68°F).