For 1990-2009 cars

### Circuit Description

The intake camshaft position (CMP) sensor produces a 1X signal for each revolution of the intake camshaft. This signal is used for startability. If the powertrain control module (PCM) does not receive a crankshaft position (CKP) sensor signal, the engine should still start based on the information from the CAM sensors. The CMP is connected directly to the PCM and consists of the following circuits:

• | The 12-volt reference circuit

• | The low reference circuit

• | The CMP sensor signal circuit

If the PCM receives an incorrect number of CMP sensor pulses in a given number of CKP sensor pulses, DTC P0341 will set.

The PCM runs two tests to diagnose the CMP sensor performance system. It uses a Near Engine Start, CMP Fast Event Based, test and an After Engine Start, CMP Slow Event Based, test. The Near Engine Start, CMP Fast Event Based, test runs first upon or during start-up. If the test fails, it will set DTC P0341. If the test passes, it will initiate the After Engine Start, CMP Slow Event Based, test and runs this test continuously unless it detects an error and sets DTC P0341.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0341 Intake Camshaft Position (CMP) Sensor Performance

### Conditions for Running the DTC

#### Near Engine Start (CMP Fast Event Based) Test

• | The engine is cranking.

• | The medium resolution is less than or equal to 10 counts.

• | DTC P0340 is not set.

#### After Engine Start (CMP Slow Event Based) Test

• | The engine is running.

• | DTCs P0335, P0336, and P0340 are not set.

• | DTC P0341 runs continuously when the above conditions are met.

### Conditions for Setting the DTC

#### Near Engine Start (CMP Fast Event Based) Test

The PCM detects the incorrect number of CMP sensor pulses in 2 revolutions of the crankshaft, which is usually within one second.

#### After Engine Start (CMP Slow Event Based) Test

The PCM detects the incorrect number of CMP sensor pulses in 2,000 revolutions of the crankshaft, which is usually within 4 minutes.

### Action Taken When the DTC Sets

• | The malfunction indicator lamp (MIL) will illuminate after 2 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 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.

• | A scan tool can clear the DTCs.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step verifies that the condition is present.

2. This step detects if there is electromagnetic interference (EMI) on the CMP sensor circuits.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn ON the ignition, with the engine OFF.
2. Clear the DTCs with a scan tool.
3. Start the engine.
4. Observe the DTC information with a scan tool.

Did DTC P0341 fail this ignition?

Go to Step 3

Go to Step 4

3 | Did any other DTCs fail this ignition cycle? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 5
4 |

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 5

Go to Intermittent Conditions

5 | Inspect the camshaft position (CMP) sensor circuits for the following conditions:

• | Routed too close to the ignition coils

• | Routed too close to after-market electrical equipment

• | Routed too close to solenoids, relays, and motors

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6 | Test for an intermittent and for a 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 10 | Go to Step 7
7 | Test for an intermittent and for a 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 10 | Go to Step 8
8 |

1. Remove the CMP sensor. Refer to Camshaft Position Sensor Replacement - Intake .
2. Inspect the CMP sensor and the camshaft reluctor wheel for the following conditions:

• | Incorrect sensor installation

• | A cracked or broken sensor

• | The sensor coming in contact with the reluctor wheel

• | Excessive air gap between the reluctor wheel and the sensor

• | Foreign material passing between the sensor and the camshaft reluctor wheel

• | Missing teeth in the camshaft reluctor wheel

3. If you find a condition with the CMP sensor or the camshaft reluctor wheel, refer to Camshaft Intake Sprocket Replacement or Camshaft Position Sensor Replacement - Intake .

Did you find and correct the condition?

Go to Step 10

Go to Step 9

9 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement - Intake . Did you complete the replacement? | Go to Step 10 | --
10 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 11

11 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK