Engine Control Module

This engine control module voltage chart is for use with a digital voltmeter to further aid in diagnosis. The voltages you get may vary due to low battery charge or other reasons, but they should be very close. The following conditions must be before testing:
- Engine at operating temperature
- Engine idling in "Close Loop" (for "Engine Run"column)
- DLC Diagnostic terminal not grounded
- "Scan tool" not installed
- All voltages showing "Battery Position Voltage (B+)" indicates battery or charging voltage






* All voltages shown "0" should read less than .5 volts.
1. Reads battery positive voltage for 2 seconds after ignition "ON" then should read 0 volts.
2. B+ with shifter in gear and clutch pedal not depressed.
3. B+ to 0 volts depending on Position of drive wheels with steering wheel cramped.
4. B+ for 2 seconds. �
5. 0 Volt
6. A/T Vehicles only