ignition coil control circuit high voltage..............
DTC P1351 CIRCUIT DESCRIPTION:
The enhanced ignition system uses the crank sensor in order to provide the timing input to the Vehicle Control Module (VCM). The VCM uses this reference pulse in order to determine the individual ignition spark timing for each cylinder
Once the VCM calculates the ignition timing, the ignition coil module on the Ignition Control (IC) circuit receives the timing signal. Each timing pulse received by the ignition coil module on the IC circuit triggers the coil module in order to operate the ignition coil. The secondary ignition voltage is induced, and then the secondary ignition voltage is sent to the distributor for distribution to each spark plug.
The IC signal voltage ranges from about 0.5 volt to 4.5 volts.
CONDITIONS FOR SETTING THE DTC:
ACTION TAKEN WHEN THE DTC SETS:
- The EST is enabled.
- The engine speed is less than 250 RPM.
CONDITIONS FOR CLEARING THE MIL/DTC:
- The VCM turns the Malfunction Indicator Lamp (MIL) ON when this DTC is reported and one failure has occurred.
- The VCM records the operating conditions at the time the Diagnostic Fails. Freeze Frame and Failure Records store this information.
- The VCM turns the MIL OFF after 3 consecutive drive trips when the test has Run and Passed and not Failed.
- A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle).
- Use the scan tool Clear Information function.
- Disconnect the VCM battery feed for 30 seconds.
A poor connection, a rubbed through wire in the insulation, or a wire broken inside the insulation will cause an intermittent.
Check for the following conditions:
- Poor connection.
- Damaged harness: Inspect the VCM harness connectors for the following conditions:
- Backed out terminals CLR 9 and BLK 18.
- Improper mating.
- Broken locks.
- Improperly formed or damaged terminals.
- A poor terminal to wire connection.
- Damage to the harness.
- Intermittent test - If the connections and the harness check OK, monitor a digital voltmeter connected between VCM terminal CLR 9 and BLK 18 while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change. This may help to isolate the location of the malfunction.
Additional Information provided courtesy of AllDATA