Crankshaft Position (CKP) Sensor
The characteristics of the signal supplied by the CKP sensor are learned by the ECM. This enables the ECM to set an adaption and support the engine misfire detection function. Due to a small variation between different drive plates and different CKP sensors, the adaption must be reset if either component is renewed, or removed and refitted. It is also necessary to reset the drive plate adaption if the ECM is renewed or replaced. The ECM supports four drive plate adaptions for the CKP sensor. Each adaption relates to a specific engine speed range. The engine speed ranges are detailed in the table below:
| ADAPTION | ENGINE SPEED, REV/MIN |
|---|---|
| 1 | 1800 - 3000 |
| 2 | 3001 - 3800 |
| 3 | 3801 - 4600 |
| 4 | 4601 - 5400 |
The CKP sensor is an inductive sensor that allows the ECM to determine the angular position of the crankshaft and the engine speed.
The CKP sensor is installed in the rear left side of the oil pan, in line with the engine drive plate. The sensor is secured with a single screw and sealed with an O-ring. A two pin electrical connector provides the interface with the engine harness.
The head of the CKP sensor faces a reluctor ring pressed into the outer circumference of the engine drive plate. The reluctor ring has 60 teeth, with 2 teeth missing. There are 58 teeth at 6° intervals, with two teeth removed to provide a reference point with a centerline that is 21° BTDC (Before Top Dead Center) on cylinder 1 of bank 2.
If the CKP sensor fails, the ECM:
- Uses signals from the CMP sensors to determine the angular position of the crankshaft and the engine speed
- Adopts a limp home mode where engine speed is limited to a maximum of 3000 rev/min.
With a failed CKP sensor, engine starts will require a long crank time while the ECM determines the angular position of the crankshaft using the CMP sensors.