P0021
DTC P0011, P0014, P0021, or P0024
Circuit Description
The camshaft position (CMP) actuator system enables the engine control module (ECM) to change the timing of the camshafts while the engine is operating. The CMP actuator solenoid signal from the ECM is pulse width modulated (PWM). The ECM controls the CMP actuator solenoid duty cycle by controlling the amount of solenoid ON time. The CMP actuator solenoid controls the advance or the retard of each camshaft. The CMP actuator solenoid controls the oil flow that applies the pressure to advance or retard the camshafts.
Ignition voltage is supplied directly to the CMP actuator solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver. If the ECM detects the desired camshaft position and the actual camshaft position angles are not within a calibrated value, this DTC sets.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
* DTC P0011 Intake Camshaft Position (CMP) System Performance Bank 1
* DTC P0014 Exhaust Camshaft Position (CMP) System Performance Bank 1
* DTC P0021 Intake Camshaft Position (CMP) System Performance Bank 2
* DTC P0024 Exhaust Camshaft Position (CMP) System Performance Bank 2
Conditions for Running the DTC
* Before the ECM can report DTC P0011, P0014, P0021, or P0024 failed, DTCs P0010, P0013, P0020, P0023, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 must run and pass.
* DTCs P0016, P0017, P0018, P0019, P0335, P0336, and P0338 are not set.
* The engine speed is more than 500 RPM.
* The engine must accelerate such that the CMP actuator system is commanded from the park position to the phased position. This is considered a cam control cycle. There must be a total of 4-10 cam control cycles for at least 2.5 seconds each in the phased position.
* The engine is operating for approximately 1.8 seconds.
* DTCs P0011, P0014, P0021, and P0024 runs continuously once the above conditions are met for more than 1 second.
Conditions for Setting the DTC
* The ECM detects the difference between the desired camshaft position and the actual camshaft position angles is more than 5 degrees.
OR
* The ECM detects the difference between the actual camshaft angle and the locked position angle is more than 1 degree.
* The condition exists for more than 4 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 4 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.
* Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
* Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
* The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views.
* The engine oil condition has a major impact on the camshaft actuator system.
* A low oil level condition may set this DTC. The engine may require an oil change. Inquire with the customer when the last oil change was performed. You may also monitor the Engine Oil Life parameter with a scan tool. Advise the customer an oil change may be required.
* Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft actuator, or timing chain can cause this DTC to set.
* For an intermittent condition, Refer to Intermittent Conditions. Intermittent Conditions
Test Description
Step 1 - Step 6:
Step 7 - Step 13:
Step 14 - Step 18:
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if there is a condition with the CMP actuator system.
6. This step is testing the ignition 1 voltage circuit of the CMP actuator solenoid for high resistance. If the voltage at the test lamp probe is not B+, there is a high resistance condition with the circuit.
7. This step is testing the control circuit of the CMP actuator solenoid for high resistance. If the voltage at the test lamp probe is not less than the specified voltage, there is a high resistance condition with the circuit.
11. This step isolates the condition. If the condition follows the CMP actuator solenoid, there is a condition with the solenoid.