Circuit Description
The Camshaft Position (CMP) Sensor indicates the camshaft position so that the Powertrain Control Module (PCM) can determine which cylinder is misfiring when a misfire is present. Whenever the PCM receives an intermittent signal from the CMP, then the CMP Resync Counter will increment. In order to set a DTC, the PCM must see a minimum number of resync's within a maximum time.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
The PCM sees more than 15 CMP sensor resyncs in 256 seconds (4 min, 16 sec.).
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles. |
| • | The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records. |
Conditions for Clearing the MIL or DTC
| • | The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
Diagnostic Aids
| • | Thoroughly check all circuitry for the following conditions: |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Physical damage to the wiring harness |
| • | Whenever the PCM sees less than 15 resyncs in 256 seconds, the counter is reset to 0. Anytime a poor connection is present, the Cam Sensor Reference Activity counter will stop incrementing and the Cam Sensor Resync Counter will increment. |
An intermittent may be caused by any of the following conditions:
| • | A poor connection |
| • | Rubbed through wire insulation |
| • | A broken wire inside the insulation |
Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
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The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.
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The counter should stop incrementing with the sensor electrical connector disconnected and set a DTC P0342. If the counter stills increments, this indicates that the PCM is malfunctioning.
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By moving the CMP sensor electrical connector, the connections at the sensor are being checked. Make sure that the electrical connector remains securely fastened.
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A poor electrical connection in any of the circuits at the CMP sensor will cause the CMP Resync Counter to increment. Anytime a poor electrical connection is present, the CMP Reference Activity counter will stop incrementing and the CMP Resync Counter will increment.
-
Program the replacement PCM and perform the Crankshaft Position System Variation Learn Procedure. Refer to the latest Techline procedures for PCM programming.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
2 |
Is DTC P0335 set? | -- | ||
3 |
Is the CMP resync counter incrementing? | -- | ||
|
Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury.
Did the CMP resync counter stop incrementing? | -- | |||
|
Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury. Wiggle the CMP sensor harness connector by hand with the engine still running. Did the CMP resync counter start to increment? | -- | |||
Was a repair necessary? | -- | |||
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | -- | ||
8 |
Was a repair necessary? | -- | ||
9 | Replace the Camshaft Position (CMP) sensor. Refer to the Camshaft Position Sensor Replacement . Is the action complete? | -- | -- | |
10 |
Does the scan tool indicate that this diagnostic has ran and passed? | -- | ||
11 | Check to see if any additional DTCs are set. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
