Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptor
DTC P0340: Camshaft Position (CMP) Sensor CircuitDTC P0341: Camshaft Position (CMP) Sensor Performance
DTC P0342: Camshaft Position (CMP) Sensor Circuit Low Voltage
DTC P0343: Camshaft Position (CMP) Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage | P0340, P0341, P0342, P0455, P0489 | P0342, P0343 | -- | P0341 |
Signal | P0342 | P0343 | P0343 | P0341 |
Low Reference | -- | P0343 | -- | P0341 |
Circuit/System Description
The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by an injector. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor and sends a signal to the ECM through the signal circuit. The CMP sensor circuits are directly connected to the ECM. The CMP sensor also determines which cylinder is misfiring. The CMP sensor circuits consist of the following:
| • | An ignition 1 voltage |
| • | A low reference |
| • | A CMP signal |
Conditions for Running the DTC
| • | The engine is operating. |
| • | The DTCs run continuously once the above condition is met. |
Conditions for Setting the DTC
P0340
The ECM detects no pulses from the CMP sensor.
P0341
The ECM detects that the CMP sensor signal voltage is erratic.
P0342
The ECM detects that the CMP sensor signal voltage is always low and the ECM detects no pulses from the CMP sensor.
P0343
The ECM detects that the CMP sensor signal voltage is always high and the ECM detects no pulses from the CMP sensor.
Action Taken When the DTC Sets
DTCs P0340, P0341, P0342, and P0343 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0340, P0341, P0342, and P0343 are Type B DTCs.
Diagnostic Aids
The following conditions can also set the DTC:
| • | Physical damage to the CMP sensor or the reluctor wheel. |
| • | Excessive play or looseness of the CMP sensor or the reluctor wheel. |
| • | Improper installation of the CMP sensor or the reluctor wheel. |
| • | Foreign material passing between the CMP sensor and the reluctor wheel. |
| • | Excessive air gap between the CMP sensor and the reluctor wheel. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electronic Ignition (EI) System Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- Engine idling, observe the scan tool DTC information parameter. DTCs P0340, P0341, P0342, and P0343 should not set.
- If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.
Circuit/System Testing
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the CMP sensor.
- Test for less than 10 ohms of resistance between the low reference circuit and ground.
- Install the MAIN fuse. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit and ground.
- Test for 10 - 12 volts between the signal circuit and ground.
- Verify that a test lamp does not illuminate between the signal circuit and ground.
- If all circuits test normal, test or replace the CMP sensor.
Notice: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
Important: The control module or the sensor may be damaged if the circuit is shorted to B+ voltage.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
| ⇒ | If less than the specified range, test the low reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If the test lamp does not illuminate, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
Repair Instructions
Perform the Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module replacement, setup, and programming |
