Circuit Description
The camshaft position (CMP) sensor is triggered by a notched reluctor wheel built onto the exhaust camshaft sprocket. The CMP sensor provides four signal pulses every camshaft revolution. Each notch, or feature of the reluctor wheel is of a different size which is used to identify the compression stroke of each cylinder and to enable sequential fuel injection. The CMP sensor is connected to the powertrain control module (PCM) by the following circuits:
| • | A 5-volt circuit |
| • | A low reference circuit |
| • | A signal circuit |
The PCM monitors the CMP sensor's performance by comparing the number of it's pulses to the CKP sensor pulses. There is a given number of CMP sensor pulses to CKP sensor pulses. If this ratio is not kept, the PCM will set DTC P0341.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0341 Camshaft Position (CMP) Sensor Performance
Conditions for Running the DTC
| • | DTCs P0106, P0107, P0108, and P0340 are not set. |
| • | The engine is running. |
| • | The manifold absolute pressure (MAP) is more than 45 kPa. |
| • | This DTC runs continuously. |
Conditions for Setting the DTC
The engine control module (ECM) detects more than 120 extra CMP signal pulses or 80 CMP pulses less than expected when compared to the CKP sensor signal pulses.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | |||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||||
2 |
Does the CMP Sensor parameter increment? | Go to Step 3 | Go to Step 4 | ||||||||
3 |
Did the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | ||||||||
4 | Test the signal circuit of the camshaft position (CMP) sensor for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 5 | ||||||||
5 | Test the low reference circuit of the CMP sensor for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 6 | ||||||||
6 | Test for an intermittent and poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 7 | ||||||||
7 | Test for an intermittent and poor connection at the CMP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | ||||||||
8 |
Did you find and correct the condition? | Go to Step 11 | Go to Step 9 | ||||||||
9 | Visually inspect the CMP reluctor wheel for the following conditions:
Did you find and correct the condition? | Go to Step 11 | Go to Step 10 | ||||||||
10 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Did you complete the replacement? | Go to Step 11 | -- | ||||||||
11 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 12 | ||||||||
12 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |||||||||
