Except Monaco and Premier
See Figure 1
Before proceeding with this test make certain that spark has been checked for at the coil. Refer to the ignition coil testing procedures. Failure to do this may lead to unnecessary diagnostic time and wrong test results.
- Check the battery voltage. It must be at least 12.4 volts to perform the test. If the battery voltage is not at least 12.4 volts, refer to General Information & Maintenance for battery charging procedures.
- Crank the engine for 5 seconds while monitoring the voltage at the coil positive (+) terminal. If the voltage remains near zero during the entire period of cranking, refer to Driveability & Emissions Controls for the On-board Diagnostic checks. The checks will test the PCM and the auto shutdown relay.
- If the voltage is at near-battery voltage and drops to zero after 1-2 seconds of cranking, refer to Driveability & Emissions Controls On-board Diagnostic procedures. The problem is likely to be related to the distributor reference pick-up circuit to the PCM.
- If the voltage remains at near battery voltage during the entire 5 seconds, with the key OFF , remove the PCM 60-way connector. Check the 60-way connector for any terminals that are pushed out or loose.
- Remove the connector to the coil positive (+) and connect a jumper wire between the battery positive (+) terminal and the coil (+) terminal.
- Using the special jumper wire shown in the illustration, momentarily ground terminal No. 19 of the 60-way connector. A spark should be generated when the ground is removed.
- If a spark is generated, replace the PCM with a new one.
- If no spark is generated, use the special jumper wire to ground the coil negative (-) terminal directly.
- If a spark is produced, inspect the wiring harness for an open circuit condition.
- If no spark is produced, replace the ignition coil with a new one.
Monaco and PremierCONVENTIONAL IGNITION SYSTEM
For diagnostic procedures covering the conventional ignition system components, including the coolant temperature sensor, Manifold Air/fuel Temperature (MAT) sensor, Manifold Absolute Pressure (MAP) sensor and the speed sensor or Crankshaft Position Sensor (CPS), refer to the electronic engine controls portion of Section 4.