Circuit Description
During cranking, the ignition control (IC) module monitors the 7X crankshaft position sensor signal. Once the IC module determines spark synchronization, 3X reference signals are sent to the powertrain control module (PCM). The PCM will command all six injectors on for one priming shot of fuel in all cylinders. After the priming, the injectors are left off for the next six fuel control reference signals, two crankshaft revolutions. This allows each cylinder a chance to use the fuel from the priming shot. During this waiting period, a cam pulse will have been received by the PCM. The PCM uses the cam signal pulses to initiate sequential fuel injection. The PCM constantly monitors the number of pulses on the cam signal circuit and compares the number of cam pulses to the number of 24 X reference pulses and the number of 3 X reference pulses being received. If the PCM receives an incorrect number of pulses on the cam reference circuit, DTC P0341 will set and the PCM will initiate injector sequence without the cam signal with a one in six chance that injector sequence is correct. The engine will continue to start and run normally, although the misfire diagnostic will be affected if a misfiring condition occurs.
Conditions for Running the DTC
The engine is running, 3X reference pulses are being received.
Conditions for Setting the DTC
CMP sensor reference pulse is not detected every engine cycle.
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
DTC P0341 can be caused by secondary components leaking high voltage into the ignition module. Inspect for the following conditions:
| • | Incorrect harness routing near secondary ignition components. |
| • | Ignition coil arcing to wiring harness or IC module, inspect the ignition coils for cracks, carbon tracking, or other signs of damage. |
| • | Secondary ignition wires arcing to wiring harness. |
If the condition is intermittent, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The cam signal on the scan tool should change each time the signal circuit is touched.
-
If the fuse is open in the jumper wire, there is a short to ground on the signal circuit.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 |
Does scan tool indicate the CMP sensor signal is present? | -- | Go to Step 3 | Go to Step 4 |
3 |
Does the DTC set? | -- | Go to Step 4 | Go to Diagnostic Aids |
4 |
Does the voltage measure near the specified value? | B+ | Go to Step 6 | Go to Step 5 |
5 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12 |
6 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 7 |
7 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12 |
Does cam signal change EACH time the signal circuit is touched? | -- | Go to Step 14 | Go to Step 9 | |
Did the fuse in the jumper wire open? | -- | Go to Step 11 | Go to Step 10 | |
10 | Test the signal circuit of the CMP sensor for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12 |
11 | Test the signal circuit of the CMP sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12 |
12 | Inspect for poor connections at PCM. 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 13 |
13 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
14 | Inspect for poor connections at 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 15 |
15 | Replace CMP sensor. Refer to Camshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- |
16 |
Does the DTC Run and Pass? | -- | Go to Step 17 | Go to Step 2 |
17 | With a scan tool, review the stored information in Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
