• | 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 |
---|---|---|---|---|
Ignition 1 Voltage | P0562, P0342, P1404 | P0342 | -- | P0341 |
CMP Sensor Signal | P0342 | P0342 | P0342 | P0341 |
Low Reference | -- | P0342 | -- | P0341 |
The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the engine control module (ECM) can determine which cylinder is ready to be fueled by an injector. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor and sends a signal to the ECM through the signal circuit. The CMP sensor circuits are directly connected to the ECM. The CMP sensor also determines which cylinder is misfiring. The CMP sensor circuits consist of the following:
• | An ignition 1 voltage |
• | A low reference |
• | A CMP signal |
• | DTCs P0335, P0336 and P0337 are not set. |
• | The engine is running. |
• | The DTCs run continuously once the above conditions are met. |
The ECM detects an incorrect CMP signal for greater than 10 crankshaft revolutions.
The ECM detects no CMP signal for greater than 1 second.
• | DTC P0341 is a Type B DTC. |
• | DTC P0342 is a Type A DTC. |
• | DTC P0341 is a Type B DTC. |
• | DTC P0342 is a Type A DTC. |
The following conditions can also set the DTC:
• | Physical damage to the CMP sensor or the reluctor wheel |
• | Excessive play or looseness of the CMP sensor or the reluctor wheel |
• | Improper installation of the CMP sensor or the reluctor wheel |
• | Foreign material passing between the CMP sensor and the reluctor wheel |
• | Excessive air gap between the CMP sensor and the reluctor wheel |
Electronic Ignition (EI) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Engine running, observe the DTC information with a scan tool. DTCs P0341 and P0342 should not set.
⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
⇒ | If the test lamp does not illuminate, repair the open/high resistance on the ground circuit. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |