P0016

DTC P0016

DTC DESCRIPTOR

DTC P0016
Crankshaft Position (CKP) Camshaft Position (CMP) Correlation

DIAGNOSTIC FAULT INFORMATION
Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION
The engine control module (ECM) uses the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor pulses to monitor the correlation between the crankshaft and camshaft. The crankshaft reluctor wheel consists of a 60-tooth pattern with 2 teeth missing for a reference gap. Each tooth is evenly spaced 6 degrees apart, except for the reference gap which has a 12 degrees space. The camshaft reluctor wheel has 4 teeth, 2 narrow and 2 wide. The 4 trailing edges of each tooth are evenly spaced 90 degrees apart. As the crankshaft rotates 2 revolutions, with the CMP actuator in the home or parked position, the ECM expects CMP sensor pulses to occur 36 degrees before top dead center (BTDC) at cylinder number 1, 96 degrees BTDC at cylinder number 3, 36 degrees BTDC at cylinder number 4, and 96 degrees BTDC at cylinder number 6.

CONDITIONS FOR RUNNING THE DTC
- DTC P0335, P0336, P0340, P0641, or P0651 is not set.
- The engine is running.
- The engine speed is less than 1,200 RPM.
- The DTC runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the CMP sensor pulses occur less than or more than 9 crankshaft degrees outside of the normal position for 25 out of 35 engine revolutions.

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 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.

CIRCUIT/SYSTEM VERIFICATION
1. Operate the vehicle at idle and at various engine speeds and load ranges while observing the CMP Variance, Desired CMP, and CMP Angle parameters with a scan tool.
2. All three parameters should remain at 0 degrees at idle. The CMP Variance should remain at 0 degrees unless the CMP actuator is being commanded. If the CMP actuator is moved, the CMP Variance will rise for 1-2 seconds until the CMP Angle parameter matches the Desired CMP parameter. The CMP Variance should again return to 0 degrees.
- If the CMP Variance remains more than 0 degrees for more than 3 seconds, continue with the Circuit/System Testing.

CIRCUIT/SYSTEM TESTING
1. With the ignition OFF, inspect the engine or review the service history of the vehicle for any recent repairs involving the timing chain, camshaft, or crankshaft.
- If recent repairs were made, refer to Timing Chain and Sprockets Replacement and inspect the timing chain and sprockets for proper alignment.
2. The supply of clean pressurized engine oil to the CMP actuator spool valve is critical to CMP actuator performance. Review the service history of the vehicle for extended intervals between oil changes. Inspect the engine oil for the following:
- Viscosity breakdown
- Incorrect viscosity or contains aftermarket additives
- Low level
- Debris or other contaminants
- Mixed with engine coolant
- Low pressure
- If the engine oil is old, burnt, contains additives, or is not the correct viscosity, change the oil and filter.
- If the engine oil level is low, refer to Oil Leak Diagnosis or Oil Consumption Diagnosis to determine the cause for the loss of oil, and repair as necessary. Component Tests and General Diagnostics Component Tests and General Diagnostics
- If the engine oil is contaminated or contains debris, determine the cause, and remove the timing chain, CMP actuator, and sprockets. Remove the filter screen in the camshaft that supplies engine oil to the CMP actuator. Inspect the screen and oil passages for debris. Replace the screen as necessary.
- If the engine oil is mixed with coolant, refer to Coolant in Engine Oil to determine the cause, and repair as necessary.
- If the engine oil pressure is low, refer to Oil Pressure Diagnosis and Testing to determine the cause, and repair as necessary. Component Tests and General Diagnostics
3. Remove the engine front cover, refer to Engine Front Cover Replacement and inspect the timing chain, tensioner, and sprockets for wear or damage
- If any parts are worn or damaged, replace as necessary.
- If everything else tests normal, replace the CMP actuator.

REPAIR INSTRUCTIONS

IMPORTANT:
- The use of oil system cleaners and additives is not recommended. Such cleaners contain strong detergents that may adversely react with seals and other engine components.
- Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Engine Oil and Oil Filter Replacement for engine oil and filter change.
- Timing Chain and Sprockets Replacement for timing chain, sprockets, and CMP actuator replacement. Verification Tests