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. The ECM compares the CMP or the camshaft angle, to the position of the crankshaft. If the ECM detects a deviation between the camshaft position target and the crankshaft position (CKP), this DTC sets.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0016 Crankshaft Position (CKP) - Intake Camshaft Position (CMP) Correlation Bank 1 |
| • | DTC P0017 Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation Bank 1 |
| • | DTC P0018 Crankshaft Position (CKP) - Intake Camshaft Position (CMP) Correlation Bank 2 |
| • | DTC P0019 Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation Bank 2 |
Conditions for Running the DTC
| • | Before the ECM can report DTC P0016, P0017, P0018, or P0019 failed, DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0335, P0336, P0338, 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. |
| • | The engine is operating for more than 5 seconds. |
| • | The engine coolant temperature is between 0-92°C (32-198°F). |
| • | The calculated engine oil temperature is less than 120°C (248°F). |
| • | DTC P0016, P0017, P0018, and P0019 run continuously once the above conditions are met for approximately 10 minutes. |
Conditions for Setting the DTC
Condition 1
| • | The ECM detects that the actual camshaft angle of a single intake camshaft is more than 20 degrees advanced in relationship to the crankshaft. |
| • | The ECM detects that the actual camshaft angle of a single exhaust camshaft is more than 25 degrees retarded in relationship to the crankshaft. |
| • | The camshafts are being commanded to the parked position. |
Condition 2
| • | The learned angle of an intake camshaft is more than 14.5 degrees advanced in relationship to the crankshaft. |
| • | The learned angle of an exhaust camshaft is more than 14.5 degrees retarded in relationship to the crankshaft. |
Either 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-A/BT-8637 GM Approved Terminal Test Kit for any test that requires probing the ECM harness connector or a component harness connector. |
| • | Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft actuator, camshaft sensor, crankshaft sensor, or timing chain can cause this DTC to set. |
| • | An actuator that is in the full advance or retard position can cause this DTC to set. |
| • | The presence of DTCs P0008 and P0009 along with P0016, P0017, P0018, and P0019 indicates a possible condition with the primary timing chain and the alignment between both intermediate sprockets and the crankshaft, or the crankshaft reluctor wheel has moved and is no longer referenced to top dead center (TDC). |
| • | Observing the desired and actual camshaft angle parameters, with a scan tool before a DTC sets, may help to isolate whether a condition is specific to one camshaft, one bank, or caused by a condition with the primary crankshaft timing. |
| • | For an intermittent condition, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if there is a condition present.
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The listed DTCs may cause this DTC to set.
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Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft or timing chain can cause this DTC to set.
Step | Action | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||
Does the scan tool display DTC P0016, P0017, P0018, or P0019 failed this ignition? | 10 Minutes | Go to Step 4 | Go to Step 3 | |||||||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids | ||||||||||||
Observe the DTC Information with a scan tool. Does the scan tool display that DTC P0010, P0013, P0020, P0023, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, or P2095 also failed this ignition? | -- | Go to Step 5 | ||||||||||||||
Repair one of the following conditions:
Refer to Camshaft Timing Drive Chain Alignment Diagram , Camshaft Timing Drive Components Cleaning and Inspection , and Crankshaft and Bearing Cleaning and Inspection . Did you complete the repair? | -- | Go to Step 6 | -- | |||||||||||||
6 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 7 | ||||||||||||
7 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||||
