P0342

CIRCUIT DESCRIPTION
The Camshaft Position (CMP) sensor works in conjunction with a 1X reluctor wheel on the camshaft. The Powertrain Control Module (PCM) provides a 12-volt reference to the CMP sensor, a low reference, and a signal circuit.

The CMP sensor determines whether a cylinder is on a firing stroke or on an exhaust stroke. When the camshaft rotates, the reluctor wheel interrupts a magnetic field that is produced by a magnet within the sensor. The sensor's internal circuitry detects this condition, and produces a signal which the PCM reads. The PCM uses this 1x signal in combination with the Crankshaft Position sensor 24X signal in order to determine the crankshaft position and the stroke. This diagnostic monitors for a loss of Camshaft Position sensor signal.

As long as the PCM receives the Crankshaft Position sensor 24X signal, the engine will start. The PCM can determine top dead center for all cylinders by using the Crankshaft Position sensor 24X signal alone. The Camshaft Position sensor 1X signal is used by the PCM in order to determine if the cylinder at top dead center is on the firing stroke, or on the exhaust stroke. The system attempts synchronization, and looks for an increase in the engine speed, indicating that the engine started. If the PCM does not detect an increase in the engine speed, the PCM assumes it incorrectly synchronized to the exhaust stroke, and re-syncs to the opposite cam position. A slightly longer cranking time may be a symptom of this condition.

CONDITIONS FOR RUNNING THE DTC
The engine speed is less than 4,000 RPM.

CONDITIONS FOR SETTING THE DTC
The PCM detects that the cam signal is stuck low when the signal should be high for 1.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC "Last Test Failed" clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
The following may cause this DTC to set:
^ Camshaft reluctor wheel damage
^ The sensor coming in contact with the reluctor wheel

For an intermittent condition, refer to Intermitten Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-8:

Steps 9-21:

The numbers below refer to the step numbers on the diagnostic table.
2. This step verities that the fault is present.
4. If the duty cycle is present at the PCM connector, the Camshaft Position sensor 12-volt reference circuits and the low reference circuits are OK.
5. This step tests the camshaft position sensor 12-volt reference circuit.
6. This step tests the camshaft position sensor low reference circuit.
9. This step tests for a short to B+ on the camshaft position sensor signal circuit.
10. This step tests for a short to ground on the camshaft position sensor signal circuit.