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 Setting the DTC
| • | The engine is running. |
| • | The CMP resync counter increments more than 15 counts in less than 256 seconds. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The PCM will record the operating conditions at the time that the diagnostic fails. The Freeze Frame and Failure Records buffers will store this information. |
| • | A history DTC stores. |
Conditions for Clearing the MIL/DTC
| • | The malfunction indicator lamp (MIL) will turn OFF after 3 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
| • | A poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation may cause an intermittent problem. |
| • | Thoroughly check any circuitry, that is suspected as causing the intermittent complaint, 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. |
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
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The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame Data and the Failure Records on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurs. Refer to this information on the scan tool later.
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This step determines if the DTC P0341 is the result of a hard failure or an intermittent condition.
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The counter should stop incrementing with the CMP sensor electrical connector disconnected. A DTC P0342 should set after two ignition cycles with the CMP sensor disconnected. When the Cam Sensor Resync Counter still increments then the PCM is faulty.
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By moving the CMP sensor electrical connector checks the connections at the sensor. Make sure the electrical connector is securely fastened.
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A poor connection in any of the circuits at the CMP sensor will cause the CMP Resync Counter to increment. Anytime a poor connection is present, the Cam Sensor Reference Activity counter will stop incrementing and the Cam Sensor Resync Counter will increment.
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Before replacing the PCM, check the terminals for improper mating, broken locks, or physical damage to the wiring harness. Reprogram the replacement PCM. Refer to the latest Techline information for programming procedures.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||
Is the CMP Resync Counter incrementing? | -- | |||
Does the CMP Resync Counter increment? | -- | |||
|
Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury. With the engine still running, wiggle the CMP sensor electrical connector by hand. Did the CMP Resync Counter start to increment? | -- | |||
Check for poor connections at the CMP sensor electrical connector and repair as necessary. Refer to Wiring Repairs in Engine Electrical. Was a repair necessary? | -- | |||
Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | ||
7 | Replace the Camshaft Position (CMP) sensor. Refer to Camshaft Position Sensor Replacement . Is the action complete? | -- | -- | |
8 |
Is the CMP Resync Counter incrementing? | -- | ||
9 |
Does the scan tool indicate that this diagnostic ran and passed? | 90°-95° C | ||
10 | Check if any additional DTCs are set. Are any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC Table | System OK |
