Ignition System No Start Test

NOTE: To prevent unnecessary diagnostic time and wrong test results, the previous Testing For Spark at Coil should be performed prior to this test.

WARNING: SET PARKING BRAKE OR BLOCK THE DRIVE WHEELS BEFORE PROCEEDING WITH THIS TEST.


PROCEDURE

NOTE: Unplug the ignition coil connector at the coil. Connect a set of small jumper wires (18 gauge) between the ignition coil and coil electrical connector.

No Start Test:

1. Determine that sufficient battery voltage (12.4 volts) is present for the starting and ignition systems.

2. 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, Check for fault codes. Check the Powertrain Control Module (PCM) and auto shutdown relay.

^ If voltage is at near-battery voltage, and drops to zero after 1-2 seconds of cranking, check the distributor reference pickup to PCM circuit. See Computers and Control Systems.

Engine Controller 60-Way Connector:

^ If voltage remains at near battery voltage during the entire 5 seconds, turn the key off. Remove the 60-way connector from the PCM. Check 60-way connector for any damaged terminals.

3. Remove test lead from the coil positive terminal. Connect an 18 gauge jumper wire between the battery positive terminal and the coil positive terminal.

Special Jumper - Ground To Coil Negative:

4. Make the special jumper shown in Figure above. Using the jumper, momentarily ground terminal number 19 of the 60-way connector. A spark should be generated at the coil cable when the ground is removed.

5. If spark is generated, replace the PCM.

6. If spark is not seen, use the special jumper to ground the coil negative terminal directly.

7. If spark is produced, repair wiring harness for an open condition.

8. If spark is not produced, replace the ignition coil.