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 malfunction indicator lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the malfunction present. |
| • | 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 number(s) below refer(s) to the step number(s) 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 the latest Isuzu Technical Communications System (ITCS) procedures for PCM reprogramming and the Crankshaft Position System Variation Learn 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 the 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 applicable DTC table | System OK |
