To test the ignition system perform the test procedures in a particular sequence. Start with the secondary spark test, commence to the coil test (located under the coil procedures later in this section) and finally perform the failure-to-start test. Performing the tests in this order will narrow down the ignition system problem in the easiest manner.
SECONDARY SPARK TEST
See Figure 1
Since there are 2 independent coils in the assembly, each coil must be checked individually. Cylinders 1 and 4, and 2 and 3 are grouped together.
- Remove the cable from the No. 1 spark plug, then insert a clean spark plug into the spark plug boot.
Due to the high secondary voltage and risk of electrical shock, it is advisable to wrap a thick, dry cloth around the boot before grasping it.
- Ground the plug to the engine (touch the spark plug metal body to the engine block or other piece of metal on the car).
- Crank the engine and look for spark across the electrodes of the spark plug.
- Repeat the test for the three remaining cylinders. If there is no spark during all cylinder tests, refer to the failure-to-start test. If one or more tests indicate irregular, weak or no spark, refer to the coil test.
See Figure 2
Before proceeding with this test, refer to the testing procedures for the ignition coil, located later in this section.
- Using a Digital Volt/Ohmmeter (DVOM) measure the voltage from the negative (-) battery terminal to the positive (+) battery terminal. The voltage should be at least 12.4 volts. This amount of voltage is necessary for an accurate inspection of the system.
- Detach the ignition coil harness connector and attach the positive (+) lead of the DVOM to the B+ terminal of the harness connector. Connect the negative lead of the DVOM to a good ground.
Crank the engine over for approximately 5 seconds while monitoring the voltage at the B+ connector terminal.
- If the voltage remains near zero during the entire period of cranking, check the Auto Shutdown (ASD) relay and PCM; refer to Driveability & Emission Controls for more details regarding Diagnosis Read-out Boxes (DRB scan tools) and PCM diagnostics.
- If the voltage is at near-battery voltage and drops to zero after 1-2 seconds of cranking, check the camshaft sensor, crankshaft sensor and their circuits. Refer to Driveability & Emission Controls for more information on testing the crankshaft and camshaft position sensors.
- If the voltage remains at near-battery voltage during the entire 5 seconds, continue with the test.
The Powertrain Control Module (PCM) is mounted to the left-hand inner fender, next to the battery.
- Turn the ignition key OFF . Remove the PCM 60-way connector. Check the 60-way connector for any terminals loose from the connector.