The camshaft position (CMP) sensor is used to correlate crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by the injector. The CMP is also used to determine which cylinder is misfiring when a misfire is present. When the ECM cannot use the information from the CMP sensor, a DTC is set, and the ECM will fuel the engine using the alternating synchronous double fire (ASDF) method.
• | A CMP sensor pulse is not detected at the correct interval every 4 cylinders. |
• | The engine is running. |
• | The malfunction indicator lamp (MIL) will illuminate after 3 consecutive trips with a fail. |
• | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers. |
• | A history DTC is stored. |
• | The MIL will turn OFF after 4 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. |
• | DTCs can be cleared by using the scan tool. |
• | Disconnect the ECM battery feed for more than 10 seconds. |
An intermittent problem may be caused by a poor connection, rubbed-through wire insulation, or a wire that is broken inside the insulation.
Any circuitry that is suspected as causing the complaint should be thoroughly inspected for the following conditions:
• | Backed-out terminals |
• | Improper mating |
• | Broken locks |
• | Improperly formed |
• | Damaged terminals |
• | Poor terminal-to-wire connection |
• | Physical damage to the wiring harness |
The numbers below refer to the step numbers on the diagnostic table.
The On-Board Diagnostic System Check prompts the technician to complete some 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 taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
This step determines if DTC P0342 is the result of a hard failure or an intermittent condition.
This step determines if voltage is available to the CMP.
This step inspects for a voltage supplied by the ECM to the CMP.
The replacement ECM must be reprogrammed. Refer to the latest Techline procedure for ECM reprogramming.
Step | Action | Values | Yes | No |
---|---|---|---|---|
Perform an On-Board Diagnostic System Check. Was the check performed? | -- | Go to Step 2 | ||
Is the camshaft position (CMP) active count incrementing? | -- | Go to Step 3 | Go to Step 4 | |
3 |
Is the CMP active counter incrementing? | -- | Go to Step 13 | Go to Step 4 |
Does the test light illuminate? | -- | Go to Step 5 | Go to Step 6 | |
5 | With a test light connected to B+, probe the CMP sensor harness connector, terminal 2. Does the test light illuminate? | -- | Go to Step 7 | Go to Step 8 |
6 | Inspect for a poor connection or open in the CMP sensor B+ feed circuit and repair as necessary. Did you find and correct the condition? | -- | Go to Step 13 | Go to Diagnostic Aids |
Using a digital voltmeter (DVM), measure the voltage between the CMP sensor harness connector, terminal 1 and ground. Does the DVM display near the specified values? | 5 V | Go to Step 11 | Go to Step 9 | |
8 | Inspect for a poor connection or open in the CMP sensor ground circuit and repair as necessary. Did you find and correct the condition? | -- | Go to Step 13 | -- |
9 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
10 | Inspect the CMP signal circuit for an open or short to ground and repair as needed. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
11 |
Did you complete the replacement? | -- | Go to Step 13 | -- |
Did you complete the replacement? | -- | Go to Step 13 | -- | |
13 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | Go to Step 14 | Go to Step 2 |
14 | Are any DTCs displayed that have not been diagnosed? | -- | Go to applicable DTC table | System OK |