Theory of Operation
The Crankshaft Position (CKP) and Camshaft Position (CMP) Sensors are hall effect type sensors. The Powertrain Control Module (PCM) provides a 5-Volt supply to the position sensor and return circuit. A notch on the crankshaft gear is used to determine the speed of the engine by the PCM. As the notch on the crankshaft speed ring or the windows in the back of the camshaft gear move past the position sensor, a signal is generated on the position sensor circuit. The PCM interprets this signal and converts it to an engine speed.
While the engine is running.
The Powertrain Control Module (PCM) detects engine speed is above a calibrated threshold.
MECHANICAL OVERSPEED OF ENGINE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC- Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1. OTHER DTCS
1. Turn the ignition on.
2. With the scan tool, read and record the freeze frame data.
3. With the scan tool, read the Engine DTCs.
Are there other Crankshaft Position Sensor DTCs set?
Repair any other Crankshaft Position Sensor DTCs.
Go To 2
2. MECHANICAL OVERSPEED OF ENGINE
NOTE: The most likely cause of this DTC is a mechanical overspeed. Examples of this could be downshifting into to low of a gear on a manual transmission or pulling a heavy load on a steep downgrade.
1. Visually inspect the engine for signs of mechanical overspeed. Such as, bent push rod, broken rocker arms, bent valves, flywheel bolts backing out, etc.
Did you notice any overspeed damage?
• Repair or replace any damaged components.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
• Test Complete.