Circuit Description
The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by the injector. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor and sends a signal to the ECM through the signal circuit. The CMP sensor circuits are directly connected to the ECM. The CMP sensor also determines which cylinder is misfiring. The circuits between the CMP sensor and the ECM consists of the following:
| • | A ground circuit |
| • | A CMP signal circuit |
If the ECM detects no pulses from the CMP sensor, DTC P0342 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0342 Camshaft Position (CMP) Sensor Low Voltage
Conditions for Running the DTC
| • | The engine is running. |
| • | DTC P0342 runs continuously when the above condition is met. |
Conditions for Setting the DTC
The ECM detects no CMP pulses in 32 camshaft rotations.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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 | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||||||||||
2 |
Did DTC P0342 fail this ignition? | -- | Go to Step 4 | Go to Step 3 | ||||||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||||||
4 |
Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms. Is the voltage within 0.6 volts of the specified value? | B+ | Go to Step 5 | Go to Step 12 | ||||||||||||
5 | Connect a test lamp between the ignition 1 voltage circuit and the low reference circuit of the CMP sensor. Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 13 | ||||||||||||
6 | Measure the voltage from the signal circuit of the CMP sensor to a good ground with a DMM. Is the voltage within the specified range? | 4.8-5.2V | Go to Step 8 | Go to Step 7 | ||||||||||||
7 | Test the signal circuit of the CMP sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 11 | ||||||||||||
8 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 9 | ||||||||||||
9 |
Important: If the reluctor wheel is damaged, replace the CMP sensor. Inspect the CMP sensor reluctor wheel for the following conditions:
Refer to Camshaft Gear Replacement in Engine Mechanical. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 10 | ||||||||||||
10 | 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 in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 14 | ||||||||||||
11 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 15 | ||||||||||||
12 |
Did you complete the repair? | -- | Go to Step 16 | -- | ||||||||||||
13 | Repair the low reference circuit of the CMP sensor for one of the following conditions:
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 16 | -- | ||||||||||||
14 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||||||||
15 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||||||||
16 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 17 | ||||||||||||
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||||
