P0023
P0023-BANK 2 CAMSHAFT 2 POSITION ACTUATOR CIRCUIT OPEN
Figure 1 - Rear view of engine 3.6L
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
NOTE:
The CMP Sensor is a dual read sensor reading both camshafts of it's correlating bank.
Variable Valve Timing (VVT) allows the Powertrain Control Module (PCM) to monitor and adjust the position of each Camshaft, based on desired torque levels and engine operating conditions. The PCM controls solenoid operated control valves located on the front of the engine. There is one solenoid for each Camshaft, used to direct oil pressure to hydraulic actuators mounted between each Camshaft and its driving sprocket. The oil pressure alters the angular position or phasing of each Camshaft relative to Crankshaft rotation. A sensor is used to monitor the position of each Camshaft.
The 3.6L has four separate Camshafts that the Powertrain Control Module (PCM) requires positional information from. There are two Camshaft Position (CMP) Sensors on the 3.6L, with each CMP Sensor consisting of four circuits. The sensors are located at the top rear of each valve cover. On the end of each Camshaft is a magnetic encoder that is programmed with a magnetic pattern. The PCM provides a 5-Volt supply and a sensor ground circuit to the CMP Sensor and the CMP Sensor provides two Camshaft positional signals, the intake and exhaust camshaft position, to the PCM. The sensor detects the magnetically encoded information, a series of magnetic peaks and valleys, from the encoder. As each Camshaft rotates, the magnetic encoded pattern passes by the CMP Sensor creating a changing magnetic field at the sensor face. The changing magnetic field is interpreted by the sensor electronics and a digital output, ON/OFF or HIGH/LOW pattern, is produced. The length of the pulse width generated by the CMP varies in size based on the velocity of the Camshaft. The PCM decodes the digital pattern to identify the Camshaft position. The information from each individual Camshaft along with the Crankshaft information is used to control and sequence the Variable Valve Timing (VVT) system and fuel injection events.
- When Monitored:
Variable Valve Timing (VVT) rationality is monitored under the following conditions: (1) Cam phasing is commanded off of the default (lockpin) position; (2) Oil temperature is between -12°C to 139°C (10°F to 282°F); (3) Battery voltage is greater than 10 Volts; (3) Engine speed is at least 650 to 1400 RPM, depending on oil temperature; (4) No CMP sensor, CKP sensor or OBDI plausibility errors. Before VVT can be enabled, reference adaptation must be completed.
- Set Condition:
The PCM detects that the Camshaft 2/2 Control circuit is open.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. PCM Pre-Diagnostic Troubleshooting Procedure.
Diagnostic Test
1. DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
NOTE: Diagnose and repair any CMP sensor or CKP sensor DTCs before continuing with this test.
NOTE: Diagnose and repair any oil pressure or oil pressure sensor DTCs before continuing with this test.
1. Start the engine and allow it to reach normal operating temperature.
WARNING:
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.
2. With the scan tool, clear DTCs in the Powertrain Control Module (PCM).
3. Test drive the vehicle under the conditions in which the DTC is monitored, as outlined above.
4. With the scan tool, select View DTCs.
Is the DTC Active or Pending at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.
2. (K277) CMP 2/2 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Camshaft 2/2 Position Solenoid/Oil Control Valve harness connector.
3. Disconnect the PCM C2 harness connector.
4. Inspect the wiring and connectors between the Camshaft 2/2 Position Solenoid/Oil Control Valve and the Powertrain Control Module (PCM).
5. Look for any chafed, pierced, pinched or partially broken wires.
6. Look for broken, bent, pushed out or corroded terminals.
7. Measure the resistance of the (K277) CMP 2/2 Control circuit between the Camshaft 2/2 Position Solenoid harness connector and the PCM C2 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 3
No
- Repair the (K277) CMP 2/2 Control circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. (K277) CMP 2/2 CONTROL CIRCUIT ACTUATION
1. Connect the PCM C2 harness connector.
2. With the scan tool, actuate the Camshaft 2/2 Position Solenoid/Oil Control Valve to the ON (maximum) position.
3. Using a 12-volt test light connected to 12 Volts, check the (K277) CMP 2/2 Control circuit in the Camshaft 2/2 Position Solenoid harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 4
No
- Replace the Camshaft 2/2 Position Solenoid. Engine Timing Cover(s) - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the VVT Exhaust Solenoid and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.