INTRODUCTION
"PIN VOLTAGE CHARTS" are supplied (when available) to reduce diagnostic time. Checking pin voltages at the electronic control unit determines if it is receiving and transmitting proper signals. Charts may also help determine if control unit harness is shorted or opened.
Note. All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in testing procedures.
Note. These ECM voltage charts along with digital voltmeter can help save diagnosis time. Voltage readings may vary slightly depending on battery voltage and alternator output.
| CAUTION | The following conditions must be met before testing |
- Engine at operating temperature.
- Engine in closed loop operation.
- Engine idling ("Engine Run" column).
- ALDL "test" terminal NOT grounded.
- "Scan" tester NOT installed.
