- Camshaft Position Sensor Performance
Diagnostic Fault Information
Circuit/System Description
The 4X camshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an
output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor
detects magnetic flux changes between the peaks and valleys of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth
rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output
pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with two narrow, and two wide output pulses per camshaft
revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of
the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to sequence the
ignition timing and fuel injection events for the engine. The ECM also uses camshaft position sensor output information to determine the camshaft
relative position to the crankshaft, to control the camshaft position actuator if equipped, and for limp-home operation.
Conditions for Running the DTC
* DTC P0641, or P0651 is not set.
* The engine is cranking or running.
* DTCs run continuously when the above conditions are met.
Conditions for Setting the DTC
Important: The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per
second, or by sensing crankshaft position sensor pulses.
* The ECM detects that the engine was started, but has received less than 2 or more than 8 camshaft position sensor pulses during the first
engine resolution.
* The ECM detects that the engine has started and is running, but receives less than 398 or more than 402 camshaft position pulses per 100
engine cycles in 800 of 1000 engine cycles.
Action Taken When the DTC Sets
* DTC P0341 is a Type B DTC.
* The camshaft position actuator, if equipped, is commanded to the parked position.
* The ignition system defaults to a failed camshaft position sensor limp home mode.
Conditions for Clearing the DTC
DTC P0341 is a Type B DTC.
Diagnostic Aids
* With this DTC set, the engine may crank for an extended period of time during start-up.
* This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test (See:
Starting and Charging/Testing and Inspection/Component Tests and General Diagnostics/Battery Inspection/Test).
Reference Information
Schematic Reference
Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Electronic Ignition System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Electronic
Ignition System Description)
Electrical Information Reference
