P1336

DTC P1336 Crankshaft Position Sensor (CKP) System Variation Not Learned




Circuit Description
In order to detect engine misfire at higher engine speeds, the Powertrain Control Module (PCM) must know of any variation between the crankshaft sensor pulse. Most variations are due to the machining of the crankshaft reluctor wheel, however, other sources of variation are also possible. A Crankshaft Position Sensor Tooth Error Correction (TEC) procedure must be performed any time a change is made to the crankshaft sensor, crankshaft, or if the PCM measures the variations and then calculates compensation factors needed to enable the PCM to accurately detect engine misfire at all speeds and loads. The Tech 2 must be used to command the PCM to learn these variations. If for any reason the PCM is unable to learn these variations or they are out of an acceptable range, the PCM will set a DTC P1336. A PCM that has not had the Crankshaft Position Sensor Tooth Error Correction (TEC) Procedure performed due to replacement or reprogramming will also set a DTC P1336. DTC P1336 is a type A code.

Conditions for Setting the DTC
- No ECT, Knock, CKP, CMP or injector sensor DTCs.
- PCM has not successfully learned crankshaft position Tooth Error Correction (TEC) within 5 attempts or 5 km (3 miles).

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate the first time the error is detected.
- The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.

Conditions for Clearing the MIL/DTC
- The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault
- DTC(s) can be cleared by using the Tech 2.

Diagnostic Aids
Refer to Tooth Error Correction (TEC) Learn Procedure

CAUTION: When performing the Crankshaft Position Sensor Tooth Error Correction (TEC) Procedure always set the vehicle parking brake and block the drive wheels. Release the throttle immediately when the engine starts to decelerate. Once the learn procedure is completed, engine control will be returned to the operator and the engine will respond to throttle position.

DTC P1336 will only set if the PCM has not learned the crankshaft position sensor Tooth Error Correction (TEC). The PCM only needs to learn this variation once per life cycle of the vehicle unless the crank sensor to crankshaft relationship is disturbed. Removing a part for inspection and then reinstalling the same part is considered a disturbance. A fully warmed up engine is critical to learning the variation correctly. If a valid learn occurs, no other learns can be completed that ignition cycle. If the engine cuts out before the specified learn procedure engine speed or at normal fuel cut-off RPM. The PCM is not in the learn procedure mode. Review the Crankshaft Position Sensor Tooth Error Correction (TEC) Procedure and re-enable the learn procedure. Verify that the Tech 2 says "Test in Progress."




Excessive Crankshaft Variation Symptom

Step 1:

Steps 2 - 3:

Steps 4 - 6:

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart:
1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the Tech 2 if applicable. This created an electronic copy of the data taken when the fault occurred. The information is then stored on the Tech 2 for later reference.
2. Engine temperature if critical to properly learn the Crankshaft Position Sensor Tooth Error Correction (TEC). Failure to properly warm the engine before performing this procedure will result in an inaccurate measurement of the Crankshaft Position Sensor Tooth Error Correction (TEC). The PCM learns this variation as the engine is decelerating and then allows engine control to be returned to the operator. All accessories must be turned OFF when learning the Crankshaft Position System angle variation. If the IAC is not disabled when the learn procedure is enable, the PCM will disable the IAC. When the PCM is ready to allow the learn procedure to run, the Tech 2 will display "Test in Progress."
3. If after the specified number attempts the PCM cannot learn the crankshaft position Sensor Tooth Error Correction (TEC) then the variation is too large and no variation problem is corrected.
4. Being unable to learn the Crankshaft Position Sensor Tooth Error Correction (TEC) indicates that the variation is out of range. Using the Excessive Crankshaft Variation Trouble shooting will help to diagnose the area where the problem lies.