• | 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 |
---|---|---|---|---|
CMP Sensor 5-Volt Reference | P0343, P0348, P0368, P0393, P0652, P2122, P2138 | P0343, P0348, P0368, P0393 | P0653, P2123, P2138 | P0341, P0346, P0366, P0391, P0652, P0653, P2138 |
CMP Sensor Signal Intake Bank 1 | P0342 | P0343 | P0343 | P0341 |
CMP Sensor Signal Intake Bank 2 | P0347 | P0348 | P0348 | P0346 |
CMP Sensor Signal Exhaust Bank 1 | P0367 | P0368 | P0368 | P0366 |
CMP Sensor Signal Exhaust Bank 2 | P0392 | P0393 | P0393 | P0391 |
Low Reference | -- | P0343, P0348, P0368, P0393 | -- | P0341, P0346, P0366, P0391 |
Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts. The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits. If the ECM detects extra or missing CMP sensor signal transitions, or a signal voltage that is more or less than the predetermined range, within a certain number of crankshaft revolutions, one of these DTCs sets.
• | The engine is operating for more than 1 second. |
• | The DTCs run continuously once the above condition is met. |
• | The ECM detects a signal from the CMP sensor, but the number of pulses are less than or more than what is expected for one crankshaft revolution. |
OR |
• | The CMP sensor does NOT correlate to the crankshaft position. |
• | Either condition must exist for more than 4 seconds, or cumulative of 50 seconds. |
The CMP sensor signal voltage is always low and the ECM detects no pulses from the CMP sensor for more than 4 seconds, or cumulative of 50 seconds.
The CMP sensor signal voltage is always high and the ECM detects no pulses from the CMP sensor for more than 4 seconds or cumulative of 50 seconds.
DTCs P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, and P0393 are Type B DTCs.
DTCs P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, and P0393 are Type B DTCs.
• | Test the current out-put of the signal circuit if you suspect high resistance in the circuit. The current out-put should be greater than 1 mA when measured on the 400 mA scale. |
• | 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
⇒ | If a DTC is set, refer to DTC P0652 or P0653 . |
Important: The control module or the sensor may be damaged if the circuit is shorted to B+ voltage.
⇒ | If greater than 5 ohms, test the low reference circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the ECM. |
⇒ | If less than the specified value, test the 5 volt reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM. |
⇒ | If the voltage is greater than specified range, test for a short to voltage in the signal circuit. If circuit/connections test normal, replace the ECM. |
Important: The signal circuit voltage can be within the specified range with a high resistance in the circuit. If this condition is suspected, refer to Diagnostic Aids.
⇒ | If the voltage is less than the specified range, test for a short to ground or an open/high resistance in the signal circuit. If circuit/connections test normal, replace the ECM. |
Perform the Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |