P0018

DTC P0018

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 ECM sends an electrical signal to the CMP actuator solenoids through the control circuits when a camshaft timing change is desired. The low reference circuit is used as a return. The CMP actuator solenoid uses electromagnetic force to pull on the plunger of the oil control valve. The oil control valve will port the pressurized engine oil to either the advancing or retarding chambers of the CMP actuator. The CMP actuator changes the camshaft position relative to the crankshaft position. If the ECM detects the difference between the desired camshaft position and the actual camshaft position angles is more than 12 degrees, DTC P0016, P0017, P0018, or P0019 will set.

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
- DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095 are not set.
- The engine is running.
- The calculated oil temperature is between -10°C to +150°C (+14°F to +302°F).
- The oil pressure is greater than 105 kPa (15 psi).
- The Low Oil Switch parameter is 0.
- The battery voltage is between 11-16 volts.
- The CMP actuator is commanded to the park position or to its full travel.
- DTC P0016, P0017, P0018, or P0019 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The ECM detects the difference between the desired camshaft position and the actual camshaft position angles is more than 12 degrees for more than 3.6 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.

The CMP Actuator System will be disabled until the end of the ignition cycle.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 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
- Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft actuator, or timing chain can cause this DTC to set.
- Inspect for a slow returning camshaft position actuator. A stuck or slow returning camshaft position actuator can cause this DTC to set.
- If the condition is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Step 1 - Step 7:

2. This step determines if the condition is present.
4. An incorrectly installed camshaft or timing chain can cause these DTCs to set.