Refer to Engine Controls Schematics
Crankshaft and Camshaft Position Sensors
.
Circuit Description
The camshaft position PCM input is produced by the ignition control module ( ICM). 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 powertrain control module (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, 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. DTC P0341 will set.
Conditions for Running the DTC
The engine is running, 3X reference pulses are being received.
Conditions for Setting the DTC
| • | The ratio of 3X reference pulses to CAM pulses received by the PCM does not equal 6 to 1. |
| • | The ratio of 3X reference pulses to 18X reference pulses received by the PCM equals 6 to 1. |
| • | The conditions are present for more than 10 seconds. |
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
An intermittent may be caused by:
| • | A poor connection |
| • | Rubbed through wire insulation |
| • | A broken wire inside the insulation |
Inspect for the following conditions:
| • | Misrouted wiring harness -- Inspect the ICM harness to ensure that it is not routed near secondary ignition components. |
| • | Malfunctioning 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 wires arcing to wiring harness -- Inspect secondary ignition wires for carbon tracking or other signs of damage. |
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step ensures that the malfunction is present.
-
This step determines whether the malfunction is being caused by a missing camshaft magnet or a malfunctioning 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 being replaced, the new PCM must be programmed.
Step | Action | Values | 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? | -- | ||||||||
Does the DTC reset? | -- | Go to Diagnostic Aids | ||||||||
3 |
Does the voltage measure near the specified value? | 5 V | ||||||||
4 |
Does the voltage measure near the specified value? | 0 V | ||||||||
5 | Does the voltage on the camshaft position input signal circuit measure more than the specified value? | 5 V | ||||||||
6 |
Did you find and correct the condition? | -- | ||||||||
7 |
Did you find and correct the condition? | -- | ||||||||
8 |
Does the voltage measure near the specified value? | B+ | ||||||||
9 | Measure the voltage between the CMP sensor signal circuit and the sensor ground circuit at the camshaft position sensor harness connector. Does the voltage measure between the specified values? | 5-7 V | ||||||||
10 |
Does the voltage switch between 0 and 5 volts when the test lamp is repeatedly touched to the CMP sensor 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 |
Did you find and correct the condition? | -- | ||||||||
15 |
Did you find and correct the condition? | -- | ||||||||
16 |
Did you find and correct the condition? | -- | ||||||||
17 |
Did you find and correct the condition? | -- | ||||||||
18 | Replace the ignition control module. Refer to Ignition Control Module Replacement . Is the action complete? | -- | -- | |||||||
19 | Replace the camshaft position sensor. Refer to Camshaft Position Sensor Replacement . Is the action complete? | -- | -- | |||||||
20 |
Did you find and correct the condition? | -- | ||||||||
Important: The magnet on the cam gear must pass the sensor in order for the test to be valid. Does voltage toggle between the specified values? | 4-0 V | |||||||||
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | ||||||||
23 | Replace malfunctioning or missing camshaft position sensor magnet. Refer to Timing Chain and Sprocket Replacement . in Engine Mechanical. Is the action complete? | -- | -- | |||||||
24 |
Does the DTC reset? | -- | System OK |
