• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Intake CMP Sensor 5-Volt Reference | P0641 | P0340 | P0340 | P0641 | P0341 |
Intake CMP Sensor Low Reference | -- | P0340 | P0340 | -- | -- |
Intake CMP Sensor Signal | P0340 | P0340 | P0340 | P0340 | -- |
The 4X camshaft position (CMP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CMP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the CMP 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 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the CMP 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 determine the optimum ignition and injection points of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home operation.
• | The engine is cranking. |
• | The medium resolution is less than or equal to 10 counts. |
• | The engine is running. |
• | DTCs P0335, P0336, and P0340 are not set. |
• | DTC P0341 runs continuously when the above conditions are met. |
The ECM detects the incorrect number of CMP sensor pulses in 2 revolutions of the crankshaft, which is usually within 1 second.
The ECM detects the incorrect number of CMP sensor pulses in 2,000 revolutions of the crankshaft, which is usually within 4 minutes.
DTC P0341 is a Type B DTC.
DTC P0341 is a Type B DTC.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | Close routing of aftermarket electrical equipment |
• | Close to solenoids, motors, and relays |
• | Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference. |
⇒ | If the sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary. |
• | The engine oil for debris |
• | The camshaft reluctor wheel for damage |
• | The timing chain, tensioner, and sprockets for wear or damage |
⇒ | If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damaged components. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection and Camshaft Cleaning and Inspection . |
Important: You must perform the Circuit/System Testing before proceeding with Component Testing.
⇒ | If the sensor is loose, incorrectly installed, or damaged, repair or replace the CMP sensor. |
⇒ | If the parameter does not increment, replace the CMP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming