P0336

DTC P0336

DTC DESCRIPTOR

DTC P0336
Crankshaft Position (CKP) Sensor Performance

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






CIRCUIT/SYSTEM DESCRIPTION
The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

CONDITIONS FOR RUNNING THE DTC
- The engine is cranking or running.
- DTC P0336 runs continuously when the above condition is met.

CONDITIONS FOR SETTING THE DTC
The ECM detects four CKP resyncs within 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM TESTING
1. Test the 5-volt reference circuit of the CKP sensor for an intermittent condition.
2. Test the low reference circuit for an intermittent condition.
3. Test the CKP sensor signal circuit for an intermittent condition.
4. Test for an intermittent and for a poor connection at the ECM.
5. Test for an intermittent and for a poor connection at the CKP sensor.
6. Remove the CKP sensor.
7. Inspect the CKP sensor for the following conditions:
- Physical damage
- Excessive play or looseness
- Improper installation
- Foreign material passing between the CKP sensor and the reluctor wheel
- Electromagnetic interference in the CKP sensor circuits
8. Inspect the CKP reluctor wheel for the following conditions:
- Physical damage
- Excessive end play or looseness
- Improper installation
9. If all circuits and components test normal, replace the CKP sensor.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Crankshaft Position (CKP) Sensor Replacement
- Engine Control Module (ECM) Replacement