• | 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 provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
5-Volt Reference Circuit | P0069, P0107, P0340, P0345, P0365, P0390, P0452, P0522, P0532, P0641, P1183, P2228 | P0340, P0345, P0365, P0390 | P0641 | -- |
CMP Sensor Signal Circuit | P0340, P0345, P0365, P0390, | P0340, P0345, P0365, P0390 | P0340, P0345, P0365, P0390 | P0341, P0346, P0366, P0391 |
Low Reference Circuit | -- | P0340, P0345, P0365, P0390 | P0340, P0345, P0365, P0390 | -- |
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 2 narrow, and 2 wide 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 sequence the ignition timing and fuel injection events of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control the CMP actuator if equipped, and for limp-home operation.
• | The engine is running. |
• | DTC P0641 is not set. |
• | These DTCs run continuously when the above conditions are met. |
The ECM detects the following:
• | Less than 4 or more than 10 CMP sensor pulses during the first 2 engine revolutions |
OR |
• | The ECM detects that the engine is running, but receives approximately 400 CMP sensor pulses per 200 engine cycles. |
• | DTCs P0341, P0346, P0366, and P0391 are Type B DTCs. |
• | The CMP actuator is commanded to the parked position. |
• | A fault on one intake CMP sensor will park both intake camshaft actuators. A fault on one exhaust CMP sensor will park both exhaust camshaft actuators. |
DTCs P0341, P0346, P0366, and P0391 are Type B DTCs.
With a DTC set, the engine may crank for an extended period of time during start-up.
Electronic Ignition (EI) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
J 35616 Connector Test Adapter Kit
• | 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. |
• | Exhaust CMP Bank 1 Active |
• | Intake CMP Bank 1 Active |
• | Exhaust CMP Bank 2 Active |
• | Intake CMP Bank 2 Active |
⇒ | If the CMP sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary. |
• | Engine oil for debris |
• | 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 root cause. Repair or replace any worn or damaged components. |
Important: You must perform the Circuit/System Testing before proceeding with Component Testing.
⇒ | If the sensor is loose, incorrectly installed, or damaged, 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 |