P0340
DTC P0340 or P0341
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0340
- Camshaft Position Sensor Circuit
DTC P0341
- Camshaft Position Sensor Performance
Diagnostic Fault Information
Circuit/System Description
The camshaft position (CMP) sensor each has 3 circuits consisting of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM uses the camshaft position sensor to determine injector and ignition system synchronization. The camshaft position sensor is also used to determine camshaft to crankshaft relationship. The ECM also uses camshaft position sensor output information to determine the camshaft relative position to the crankshaft to control camshaft phasing and limp-home operation.
Conditions for Running the DTC
P0340 Condition 1
* The starter is engaged and the engine control module detects camshaft position (CMP) sensor pulses.
* DTCs P0101, P0102 and P0103 are not set.
* The airflow into the engine is greater than 3 g/s.
Condition 2
* The engine is running.
* The starter is not engaged.
* DTC P0641 is not set.
Condition 3
* The crankshaft is synchronized.
* The starter is engaged and then disengaged.
* DTC P0335, P0336, P0641, or P0651 is not set.
Condition 4
* The crankshaft is synchronized.
* DTC P0335, P0336, P0641, or P0651 is not set.
P0341 Condition 1
* The crankshaft is synchronized.
* The starter is engaged and then disengaged.
* DTC P0335, P0336, P0641, or P0651 is not set.
Condition 2
* The crankshaft is synchronized.
* DTC P0335, P0336, P0641, or P0651 is not set.
The DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
P0340 Condition 1
The ECM does not detect a camshaft position sensor pulse for greater than 5.5 s or greater than 4.0 s since the time the starter has been engaged.
Condition 2
The ECM detects less than 4 camshaft position sensor pulses for greater than 3.0 s.
Condition 3
The ECM does not detect a camshaft position sensor pulse during the first 2 engine revolutions.
Condition 4
The ECM does not detect a camshaft position sensor pulse during 200 engine revolutions.
P0341 Condition 1
The ECM detects less than 2 or greater than 8 camshaft position sensor pulses for during the first 2 engine revolutions.
Condition 2
The ECM detects less than 398 or greater than 402 camshaft position sensor pulses during 200 engine revolutions.
Action Taken When the DTC Sets
* DTCs P0340 and P0341 are Type B DTCs.
* The camshaft position actuator is commanded to the Home or Parked position.
* The ignition system defaults to a failed camshaft position sensor limp home mode.
Conditions for Clearing the MIL/DTC
DTCs P0340 and P0341 are Type B DTCs.
Diagnostic Aids
With a DTC set, the engine may crank for an extended period of time at start-up
Reference Information
Schematic Reference
Engine Controls Schematics (LS3) [1][2]Electrical DiagramsEngine Controls Schematics (LS7) [1][2]Electrical DiagramsEngine Controls Schematics (LS9) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views 5 Bow Lowered Switch (CM7)
Description and Operation
Electronic Ignition System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify DTC P0641 or P0651 is not set.
• If any of the DTCs are set
Refer to DTC P0641 or P0651 (ECM With Supercharger) DTC P0641 or P0651 (ECM Without Supercharger) Powertrain Management (ECM Without Supercharger).
• If none of the DTCs are set
3. Engine running.
4. Verify the scan tool Camshaft Position Active Counter parameter increments.
• If the counter does not increment
Refer to Circuit/System Testing.
• If the counter increments
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
6. Verify the DTC does not set.
• If the DTC sets
Refer to Circuit/System Testing.
• If the DTC does not set
7. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B23 Camshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the low reference circuit terminal B and ground.
• If 5 ohms or greater
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If 2 ohms or less, replace the K20 Engine Control Module.
• If less than 5 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance.
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms , replace the K20 Engine Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
5. Test for 4.8-5.2 V between the signal circuit terminal C and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance.
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
6. Verify DTC P0341 is not set.
• If the DTC is set
Inspect for the conditions listed below:
* Excessive play or looseness of the B23 Camshaft Position Sensor or the reluctor wheel
* Improper installation of the B23 Camshaft Position Sensor
* Foreign material passing between the B23 Camshaft Position Sensor and the reluctor wheel
* Damaged reluctor wheel
* Excessive air gap between the B23 Camshaft Position Sensor and the reluctor wheel
* Engine oil for debris
* Timing chain, tensioner, and sprockets for wear or damage
• If any of the conditions above are found, repair as necessary.
• If all components test normal, replace the B23 Camshaft Position Sensor.
• If the DTC is not set
7. Replace the B23 Camshaft Position Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Camshaft Position Sensor Replacement Service and Repair
* Control Module References Control Module References for engine control module replacement, programming, and setup