Crankshaft Position System Variation Learn Procedure
The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set:
- Install a scan tool.
- Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List.
- Select the crankshaft position variation learn procedure with a scan tool.
The scan tool instructs you to perform the following:
NOTEVehicle must remain in Park or Neutral. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
CAUTIONWhile the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.
Accelerate to wide open throttle (WOT)
Crankshaft position (CKP) sensors activity--If there is a CKP sensor condition, refer to the applicable DTC
Enable the CKP system variation learn procedure with the scan tool and perform the following:
- Accelerate to WOT.
- Release throttle when fuel cut-off occurs.
- The scan tool displays Learn Status: Learned this ignition.
- If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete.
- If the scan tool indicates DTC P0315 failed or did not run, refer to DTC P0315 in Diagnostic Trouble Codes List.
- If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List .
- Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
The Crankshaft Position (CKP) sensor is a 3-wire sensor based on the magneto resistive principle. A magneto resistive sensor uses 2 magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The CKP sensor returns a digital ON/OFF pulse 24 times per crankshaft revolution. The pulse width encoding pattern is used to synchronize the coil firing sequence with the crankshaft position. The CKP sensor is used for ignition timing, fuel injector timing, misfire diagnostics, and tachometer display. The powertrain control module (PCM) supplies a 12-volt reference, a low reference, and a medium resolution engine speed signal circuit to the CKP sensor.
The crankshaft reluctor wheel is mounted in the middle of the crankshaft. The wheel is comprised of three 120-degree segments. Each segment represents a pair of cylinders at top dead center (TDC), and is further divided into six 20-degree segments. Within each 20-degree segment is a notch of 2 different sizes. Each 120-degree segment has a unique pattern of notches. This is known as pulse width encoding. This pulse width encoding pattern allows the PCM to quickly recognize which pair of cylinders are at TDC. The reluctor wheel is also a dual track, or mirror image, design. This means there is an additional wheel pressed against the first wheel with a gap of equal size to each notch of the mating wheel. When one sensing element of the CKP sensor is reading a notch, the other is reading a set of teeth. The resulting signals are then converted into a digital square wave output by the circuitry within the CKP sensor.
Removal & Installation
- Remove the negative battery cable.
- Raise vehicle on hoist.
- Position catalytic converter out of the way.
- If equipped, disconnect the block heater electrical connector.
- Disconnect the electrical connector.
- Remove the retaining bolt.
- Remove the sensor from the engine.
- If the sensor is not being replaced inspect for wear, cracks, or leakage. Replace the O-ring if necessary.
- Lubricate the new O-ring with clean engine oil before installing.
- Install the sensor into the block.
- Reinstall the retainer bolt to hold sensor to block face. Tighten the bolt to 97 inch lbs. (11 Nm).
- Connect the electrical connector.
- Connect the block heater electrical connector, if equipped.
- Reposition and properly install the catalytic converter.
- Lower the vehicle. Reconnect the negative battery cable.
- Remove the exhaust manifold.
- Disconnect the sensor electrical connector.
- Remove the CKP sensor bolt.
- Remove the CKP sensor.
- Lubricate the CKP sensor O-ring with clean engine oil.
- Install the CKP sensor.
- Install the CKP sensor stud and tighten to 89 inch lbs. (10 Nm).
- Connect the sensor electrical connector.
- Install the exhaust manifold.