Failure to Start Test

Fig. 24 Square Wave Pattern In Crankshaft Degrees:

This no-start test checks the camshaft position sensor and crankshaft position sensors.

The PCM supplies 8 volts to the camshaft position sensor and crankshaft position sensor through one circuit.
- If the 8-volt supply circuit shorts to ground, neither sensor will produce a signal (output voltage to the PCM).

When the ignition key is turned and left in the ON position, the PCM automatically energizes the auto shutdown (ASD) relay. However, the controller de-energizes the relay within one second if it has not received a crankshaft position sensor signal indicating engine rotation.

During cranking, the ASD relay will not energize until the PCM receives a crankshaft position sensor signal. If a crank or cam signal is missing during cranking, the respective DTC will be set within 11 seconds.

1. Check battery voltage. Voltage should be approximately 12.66 volts or higher to perform failure to start test.

Fig. 25 Coil Harness Connector:

2. Disconnect the harness connector from the coil pack (Fig. 25).

CAUTION: When testing the various sensors, be sure that the harness wires are not damaged by the test meter probes.

3. Touch a test light to the B+ (battery voltage) terminal of the coil electrical connector and ground.
- The center terminal of the connector supplies battery voltage.
4. Turn the ignition key to the ON position. The test light should flash On and then Off. Do not turn the Key to the OFF position, leave it in the ON position.
a. If the test light flashes momentarily, the PCM grounded the auto shutdown (ASD) relay Proceed to step 5.
b. If the test light did not flash, the ASD relay did not energize. The cause is either the relay or one of the relay circuits. Use the DRB or equivalent scan tool to test the ASD relay and circuits. Refer to the electrical diagrams for circuit information.
5. Crank the engine. (If the key was placed in the OFF position after step 4, place the key in the On position before cranking. Wait for the test light to flash once then crank the engine.)
a. If the test light momentarily flashes during cranking, the PCM is not receiving a camshaft position sensor signal. Use the DRB or equivalent scan tool to test the camshaft position sensor and sensor circuits. Refer to the electrical diagrams for circuit information.
b. If the test light did not flash during cranking, unplug the camshaft position sensor connector. Turn the ignition key to the OFF position. Turn the key to the ON position, wait for the test light to momentarily flash once, then crank the engine.
- If the test light momentarily flashes, the camshaft position sensor is shorted and must be replaced.
- If the light did not flash when the engine was cranked, the cause of the no-start is in either the crankshaft position sensor/camshaft position sensor 8-volt supply circuit, or the crankshaft position sensor 5-volt output or ground circuits. Use the DRB or equivalent scan tool to test the crankshaft position sensor and the sensor circuits. Refer to the electrical diagrams for circuit information.