P054C-COLD START EXHAUST CAMSHAFT POSITION TIMING OVER-ADVANCED - BANK 2 SENSOR 2
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
Cam phasing is required on a cold start in order to meet the emissions targets. On cold starts, the Powertrain Control Module (PCM) sets the Camshafts to predetermined position and monitors the Camshafts to ensure that they are in the desired positions.
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When Monitored:
First 20 seconds after engine start, as long as the engine has been off for at least 1 hour, engine coolant temperature has dropped at least 7°C (18°F), and the vehicle is NOT driven over two mph.
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Set Condition:
If the actual cam position is more than 7° advanced (angular variation) from its desired position for at least 4 seconds, this DTC is set.
NOTE: This diagnostic only applies to the Exhaust Camshaft on Bank 2.
POSSIBLE CAUSES |
|---|
| RESTRICTED INTAKE AIR SYSTEM |
| LOW BATTERY VOLTAGE |
| FUEL CONTAMINATION |
| CAMSHAFT POSITION SENSOR WIRE HARNESS |
| TONE WHEEL/PULSE RING |
| CAMSHAFT POSITION SENSOR |
| ETC MOTOR/THROTTLE BODY |
| TIMING CHAIN |
For a complete wiring diagram, refer to the Wiring Information.
| NOTE: |
During a cold start, if the engine speed drops below a calibrated minimum idle speed threshold, the base engine control monitor in the PCM will put the Camshafts back to lock pin. The Camshafts will stay at lock pin until the engine speed goes back above a calibrated threshold. During this period the Cold Start Phasing monitor sees the Camshafts at lock pin and outside of the calibrated limit and fail. Therefore, anything that can cause a stumble or dip in idle speed at start up can cause this DTC to set. |
| NOTE: |
If this fault is not accompanied by any other variable valve timing faults, it is unlikely that the Camshaft or Cam phasing hardware is at fault. |
| NOTE: |
Low battery voltage can also cause excessive current draw, in very hot and very cold ambient temperatures. Make sure the battery can pass a load test before continuing. |
| 1. | Remove and inspect the Air Filter and air intake duct work. |
Is the Air Filter dirty or any restrictions found?
Yes
- Replace the Air Filter or remove the obstruction.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 2
| 1. | Inspect the fuel for contamination. (Dirt, water, or other foreign material) |
Is the fuel contaminated?
Yes
- Drain the Fuel from the fuel tank into an approved gas holding tank and add clean fuel. (Refer to 14 - Fuel System/Fuel Delivery - Standard Procedure) .
No
- Go To 3
| 1. | Turn the ignition off. |
| 2. | Remove the Air Cleaner Assembly from the Throttle Body. |
| 3. | Check for any signs of a foreign material (ice, dirt, or excessive carbon build up) on the Throttle Plate or in the bore causing the Throttle Plate to stick. |
Were any signs of foreign material or scoring of the throttle plate or bore found?
Yes
- Remove the debris if possible or replace the Throttle Body Assembly. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 4
4. EXCESSIVE RESISTANCE IN THE (K124) ETC POSITIVE CIRCUIT
| 1. | Turn the ignition off. |
| 2. | Disconnect the PCM C2 harness connector. |
Do not probe the PCM harness connectors.
Probing the PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install the PCM Pinout Box
along with the Adapter to
perform the diagnosis.
CAUTION:
| 3. | Using a Voltmeter perform a voltage drop test. Back probe the (K124) ETC Positive circuit at the Throttle Body harness connector and probe the appropriate terminal of the 8815A . Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. |
When the engine is operating, do
not stand in direct line with the fan. Do not put your hands near
the pulleys, belts or fan. Do not wear loose clothing. Failure to
follow these instructions may result in possible serious or fatal
injury.
WARNING:
| 4. | Start the engine and allow it to idle. |
| 5. | Monitor the Voltmeter. |
Is the voltage below 0.2 volts?
Yes
- Go To 5
No
- Repair the excessive resistance in the (K124) ETC Positive circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
5. EXCESSIVE RESISTANCE IN THE (K126) ETC NEGATIVE CIRCUIT
| 1. | Turn the ignition off. |
| 2. | Move the Voltmeter leads to back probe the (K126) ETC Negative circuit at the Throttle Body harness connector and to probe the appropriate terminal of the PCM Pinout Box. Make sure the Voltmeter leads are connected so a positive polarity is displayed on the Voltmeter. |
When the engine is operating, do
not stand in direct line with the fan. Do not put your hands near
the pulleys, belts or fan. Do not wear loose clothing. Failure to
follow these instructions may result in possible serious or fatal
injury.
WARNING:
| 3. | Start the engine and allow it to reach normal operating temperature. |
| 4. | Monitor the Voltmeter. |
Is the voltage below 0.2 volts?
Yes
- Go To 6
No
- Repair the excessive resistance in the (K126) ETC Negative circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
6. CAMSHAFT POSITION SENSOR CIRCUIT WIRING OR CONNECTORS
| 1. | Turn the ignition off. |
| 2. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Camshaft Position Sensor and the Powertrain Control Module (PCM). |
| 3. | Look for any chafed, pierced, pinched or partially broken wires. |
| 4. | Verify that there is good pin to terminal contact in the Crankshaft Position Sensor and the Powertrain Control Module connectors. |
| 5. | Look for broken, bent, pushed out or corroded terminals. |
| 6. | Inspect the Camshaft Position Sensor for conditions such as loose mounting screws, damage or cracks. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No