P0340

Schematic:

CIRCUIT DESCRIPTION
The Camshaft Position (CMP) sensor works in conjunction with a single tooth reluctor wheel on the bank 2 intake camshaft. The Engine Control Module (ECM) pulls up the CMP sensor signal circuit to 5 volts and monitors this voltage. As the reluctor wheel tooth rotates past the sensor, the sensors internal circuitry pulls the signal circuit to ground, creating a square wave signal that is used by the ECM. The reluctor wheel tooth covers 180 degrees of the camshaft circumference. This causes the CMP signal voltage to transition once per crankshaft revolution. This signal, when combined with the Crankshaft Position (CKP) sensor signal, enables the ECM to determine exactly which cylinder is on a firing stroke. The ECM can then properly synchronize the ignition system, the fuel injectors, and the knock control. Note: that as long as the CKP signal is available, the engine can start and run, even if there is no CMP sensor signal the ECM will default to a non-sequential fuel injector operation.

CONDITIONS FOR RUNNING THE DTC
The engine speed is more than 20 RPM.

CONDITIONS FOR SETTING THE DTC
The CMP signal is incorrect for at least 5 cycles.

ACTION TAKEN WHEN THE DTC SETS
^ The ECM illuminates the Malfunction Indicator Lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.
^ The ECM will use a calculated spark retard value in order to minimize a knock during conditions when a knock is likely to occur. The calculated value will vary based on the engine speed and load.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The ECM turns OFF the MIL after 3 consecutive drive trips that the diagnostic runs and passes.
^ A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emissions related diagnostic.
^ The scan tool clears the MIL/DTC.

DIAGNOSTIC AIDS
Use the J 35616-A connector test adapter kit for any test that requires probing the ECM harness connector or a component harness connector. Using this kit prevents damage to the harness or component terminals. Refer to Using Connector Test Adapters in Diagrams. For an intermittent, refer to Symptoms. Symptom Related Diagnostic Procedures

Check for the following conditions:
^ Poor connections at the ECM or at the component-Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
^ Damaged harness-Inspect the wiring harness for any damage. If the harness appears to be OK, monitor the resistance of the circuit while moving the harness in different locations. A fluctuation in the resistance will indicate the area of a possible concern.
^ Check the sensor for a proper installation. A sensor that is loose or not fully seated, causing an excessive air gap between the sensor and the reluctor wheel, may cause this DTC to set.

IMPORTANT: The CMP sensor ground is shared with the MAF sensor, ECT sensor, and the TP sensor. Do not use a test lamp to test the continuity of this circuit back through the ECM. Damage to the ECM will result.

^ If other DTCs are set that share the same ground circuit, test the point where the circuits splice and where the circuit connects to the ECM for opens or high resistance.

If a repair is necessary refer to Wiring Repairs or Connector Repairs in Diagrams.

TEST DESCRIPTION

Steps 1 - 3:

Steps 4 - 11:

Steps 12 - 19:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for proper switched B+ voltage to the sensor.
4. This step tests the integrity of the CMP sensor ground circuit through the ECM to battery ground.
5. This step tests for the proper ECM pull-up voltage to the sensor.
6. This step verifies that the CMP sensor can produce a signal to the ECM.