Pin Voltage Chart
NOTE:
Unless stated otherwise in testing procedures, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance. Voltage readings may vary slightly due to battery condition or charging rate.
Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the Electronic Control Module (ECM) determines if it is receiving and transmitting proper voltage signals. Charts may also help determine if ECM wiring harness is shorted or open. See Fig 1 .
NOTE:
Following conditions must be present before testing pin voltages:
- Engine At Normal Operating Temperature.
- Engine Idling In Closed Loop (ENG. RUN Column).
- ALDL Test Terminal Not Grounded.
- Scan Tool Not Installed.
- All B+ Voltages Indicate Charging Or Battery Voltage.
- All "0" voltages are ground circuits (should read less than 0.50 volt).