Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

No Start (NS) Description

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

Through a common circuit, the Powertrain Control Module (PCM) supplies 5 Volts to the camshaft position sensor and crankshaft position sensor. The sensors supply input signals to the PCM. If the 5-Volt supply circuit shorts to ground, neither sensor will produce a signal.

When the ignition key is turned and left in the On position, the PCM automatically energizes the Auto Shutdown (ASD) relay However, the PCM will de-energizes the relay within one second because if it has not received a crankshaft signal indicating engine rotation.

During cranking, the ASD relay will not energize until the PCM receives a crankshaft position sensor signal. Secondly, the ASD relay remains energized only if the PCM senses a camshaft position sensor signal immediately after detecting the crankshaft position sensor signal.
1. Check battery voltage. Voltage should be approximately 12.66 Volts or higher to perform failure to perform test.
2. Disconnect the harness connector from one of the coil packs.
3. Connect a test light to the B+ (battery voltage) terminal of the coil electrical connector and ground. The wire for the B+ terminal is dark green with an orange tracer.
4. Turn the ignition key to the ON position. The test light should flash On and then Off. Leave the ignition key 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 scan tool to test the ASD relay and circuits. Refer to Testing and Inspection.
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 scan tool to test the camshaft position sensor and sensor circuits. Refer to Testing and Inspection.
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, the cause of the no-start is in either the:
- Crankshaft position sensor 5 Volt supply circuit
- Camshaft position sensor 5-Volt supply circuit
- Crankshaft position sensor 5-Volt output
- or ground circuits.
6. Use the DRB scan tool to test the crankshaft position sensor and the sensor circuits. Refer to Testing and Inspection.