Circuit Description
The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the Powertrain Control Module (PCM) can determine which cylinder is ready to be fueled by the injector. The CMP sensor also determines which cylinder is misfiring when a misfire is present. If the PCM receives an intermittent signal from the CMP, then the CMP Resync Counter will increment. When the PCM cannot use the information from the CMP sensor, a DTC is set and the PCM will fuel the engine by using the alternating synchronous double fire (ASDF) method.
Conditions for Setting the DTC
| • | The engine is running. |
| • | The PCM sees more than 15 CMP sensor resyncs in 256 seconds (4 min, 16 sec). |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) illuminates. |
| • | The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers. |
| • | A history DTC stores. |
| • | The coolant fan turns ON. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after three 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. |
| • | The MIL/DTCs can be cleared by using the scan tool. |
Diagnostic Aids
| • | An Intermittent problem may be caused by the following conditions: |
| - | A poor electrical connection |
| - | Rubbed-through wire insulation |
| - | A broken wire inside the insulation |
| • | Check any suspected circuitry for the following conditions: |
| - | Backed-out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal-to-wiring connections |
| - | Physical damage to the wiring harness. |
| • | If the PCM sees less than 15 resyncs in 256 seconds, the counter is reset to 0. Anytime a poor electrical connection is present, the CMP Reference Activity counter will stop incrementing and the CMP 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 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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This step determines if the DTC P0341 is the result of a hard malfunction or an intermittent condition.
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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.
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Reprogram the replacement PCM and perform the crankshaft position system variation procedure. Refer to PCM Replacement/Programming for PCM reprogramming and CKP System Variation Learn Procedure for the crankshaft position system variation learn procedure.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
2 |
Is DTC P0335 set? | -- | ||
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 electrical connector by hand with the engine still running. Did the CMP Resync Counter start to increment? | -- | |||
Was a repair necessary? | -- | |||
Is the action complete? | -- | -- | ||
8 |
Was a repair necessary? | -- | ||
9 | Replace the Camshaft Position (CMP) sensor. Refer to Camshaft Position Sensor Replacement . Is the action complete? | -- | -- | |
10 |
Is the CMP Resync Counter incrementing? | -- | ||
11 |
Does the scan tool indicate that this diagnostic has ran and passed? | -- | ||
12 | 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 |
