Start by testing the ignition coil primary, and secondary resistance.
To measure the primary resistance, connect an ohmmeter between the positive (+) and negative (-) terminals (the terminals which are connected to the engine wiring harness) on the coil. To test the secondary resistance, connect an ohmmeter between the positive (+) coil terminal and the high voltage cable terminal on the coil. Then, measure the resistance between the positive (+) coil terminal and the coil case; the resistance for the case should exhibit infinite resistance. For coils manufactured by Diamond, the primary resistance at 70-80°F (21-27°C) should be 0.97-1.18 ohms and the secondary resistance should be 11,300-15,300 ohms. Coils built by the Toyodenso company should exhibit a primary resistance at 70-80°F (21-27°C) of 0.95-1.20 ohms and a secondary resistance of 11,300-13,300 ohms. Replace any coil with a new one if it does not meet the specifications.
FAILURE-TO-START TEST
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.
CAUTION Be sure to apply the parking brake and block the wheels before performing any test with the engine running.
- 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 Section 1 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 Section 4 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 Section 4 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.
TESTING
- Check for stored trouble codes, then proceed as follows:
- Fault code 11 - proceed to the next step.
- Fault code 54 - proceed to step 6.
NOTE: Before proceeding, verify that a minimum of 12.4 volts is available from the battery for operation of cranking and ignition systems.
- Test the distributor pick-up signal reference circuit as follows:
- Turn the ignition switch to the OFF position.
- Unplug the distributor pick-up connector.
- Remove the coil wire from the distributor cap and have an assistant hold it 1⁄4 in. (6mm) from a good engine ground.
- Turn the ignition switch to the ON position.
- Connect a jumper wire to the gray (GY) wire terminal and touch the other end of the jumper wire to the black/light blue (BK/LB) wire terminal on the distributor harness connector several times. While performing this, observe the coil wire.
- If there is spark from the coil wire, proceed to the next step
- If there is no spark from the coil wire, the problem is in the engine controller or wiring.
- Check the power supply to the distributor reference pick-up as follows:
- Turn the ignition switch to the ON position.
- Connect a voltmeter between the orange wire in the harness connector and a known good ground.
- If the reading on the voltmeter is 8-9.5 volts, proceed to the next step.
- If the reading is anything but 8-9.5 volts, check for problems in the circuit between the reference connector and the engine controller.
- Check the mechanical operation of the distributor as follows:
- Turn the ignition switch to the OFF position.
- Remove the distributor cap from the distributor housing.
- Crank the engine while observing the ignition rotor.
- If the distributor rotor revolves while the engine is being cranked over, replace the distributor pick-up coil assembly with a new one.
- If the distributor rotor did not rotate, inspect the engine for a mechanical fault and repair as necessary.
- If fault code 54 (No distributor sync pick-up signal) is being received, or was received before performing this test, proceed as follows:
- Turn the ignition switch to the OFF position.
- Unplug the distributor pick-up connector.
- Connect a voltmeter to the tan/yellow (TN/YL) wire of the harness connector.
- Turn the ignition switch to the ON position.
- If the reading on the voltmeter is at 4 volts, replace the distributor pick-up coil assembly.
- If the reading is 0 volts, check for an open in the wiring harness between the reference connector and the engine controller.
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