Circuit Description
The camshaft position PCM input is produced by the ignition control module. The ICM produces the camshaft position PCM input by filtering the Camshaft Position (CMP) sensor pulses when the engine is running and CKP sync pulses are also being received. The PCM uses the camshaft position PCM input pulses to initiate sequential fuel injection and to determine crankshaft position for the misfire diagnostic. The PCM constantly monitors the number of pulses on the camshaft position PCM input circuit and compares the number of camshaft position PCM input pulses to the number of 18X reference pulses and the number of 3X reference pulses being received. If the PCM receives an incorrect number of pulses on the camshaft position PCM input circuit, DTC P0341 will set and the PCM will initiate injector sequence without the camshaft position PCM input 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 disabled.
Conditions for Running the DTC
The engine is running (3X reference pulses are being received).
Conditions for Setting the DTC
No cam sensor reference pulses are not received in one engine cycle (720 degrees of crankshaft rotation).
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 and Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been 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 the scan tool. |
Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following conditions:
| • | Faulty Ignition Coil - Remove the ignition coils and inspect the ignition control module and coils for cracks, carbon tracking, or other signs that indicate that the coil secondary circuit is arcing to the ICM or ICM wiring harness. Refer to Ignition Coil Replacement . |
| • | Secondary ignition wire(s) arcing to wiring harness - Check secondary ignition wires for carbon tracking or other signs of damage. |
| • | Poor connection at the PCM - Inspect harness connectors for the following conditions: |
| - | Backed out terminals. |
| - | Improper mating. |
| - | Broken locks. |
| - | Improperly formed or damaged terminals. |
| - | Poor terminal to wire connection. |
| • | Damaged harness - Inspect the wiring harness for damage. |
| • | If the harness appears to be OK, disconnect the PCM, turn the ignition on and observe a voltmeter connected to the CAM signal circuit at the PCM harness connector while moving connectors and wiring harnesses related to the ICM and the CMP sensor. A change in voltage will indicate the location of the fault. |
Review the Freeze Frame/Fail Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
-
Ensures that the fault is present.
-
Determines whether the fault is caused by a missing camshaft magnet or a faulty PCM. The voltage measured in this step should read around 4 volts, toggling to near 0 volts when the CMP sensor interfaces with the camshaft magnet.
-
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 |
Important:: If the engine cranks but will not run, refer to Engine Cranks but Does Not Run . Did you perform the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||
Does the scan tool indicate this DTC failed this ignition? | -- | Go to Diagnostic Aids | ||||||
3 |
Important: If voltage measures 0, bump over engine to insure cam sensor magnet is not located under the cam sensor at the time of this test. Does the voltage measure near the specified value? | 5V | ||||||
4 |
Important:
Does the voltage toggle from 5 volts to 0 volts as the magnet is placed on the sensor? | -- | ||||||
5 | Does the voltage on the camshaft position input signal circuit measure more than the specified value? | 5V | ||||||
6 |
Did you find and correct the condition? | -- | ||||||
7 |
Did you find and correct the condition? | -- | ||||||
8 |
Is the voltage at the specified value? | B+ | ||||||
9 | Measure the voltage on the CMP sensor signal circuit using a DMM that is connected to the CMP ground circuit. Does the voltage measure within the specified range? | 5-7V | ||||||
10 |
Does the voltage switch between 0 and 5 volts when the test lamp is repeatedly touched to the CMP signal circuit? | -- | ||||||
11 |
Did you find and correct the condition? | -- | ||||||
12 |
Did you find and correct the condition? | -- | ||||||
13 |
Did you find and correct the condition? | -- | ||||||
14 | Inspect for poor connections at the ICM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||||||
15 | Inspect for poor connections at the CMP sensor. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||||||
16 | Test for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||||||
17 | Inspect for the following conditions:
Did you find and correct the condition? | -- | ||||||
18 | Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement? | -- | -- | |||||
19 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Did you complete the replacement? | -- | -- | |||||
20 | Inspect for the following conditions:
Did you find and correct the condition? | -- | ||||||
Does the voltage toggle between the specified values? | 5V / 0V | |||||||
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | ||||||
23 | Replace faulty or missing CMP sensor magnet. Did you complete the replacement? | -- | -- | |||||
24 |
Does the DTC reset? | -- | System OK |
