P0335

DTC P0335

DTC DESCRIPTOR

DTC P0335
Crankshaft Position (CKP) Sensor Circuit

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 is a variable reluctance sensor. The CKP sensor indicates the crankshaft speed and position. The CKP sensor produces an AC voltage of different amplitude and frequency. The frequency depends on the velocity of the crankshaft. The AC voltage output depends on the CKP and the battery voltage. The CKP sensor works in conjunction with a 58X reluctor wheel attached to the crankshaft. The CKP sensor connects to the engine control module (ECM) through the following circuits:
- The 5-Volt reference circuit
- The CKP sensor signal circuit
- The low reference circuit

CONDITIONS FOR RUNNING THE DTC
- The engine is cranking or running.
- DTC P0335 runs continuously when the above condition is met.

CONDITIONS FOR SETTING THE DTC
- The ECM detects an incorrect number of CKP pulses during engine cranking for 4 seconds.
- The ECM detects an incorrect number of CKP pulses while the engine is running for 2 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.

DIAGNOSTIC AIDS
- When the ECM enables starter operation, the ECM also initiates the diagnostic test routines for the CKP and camshaft position (CMP) sensors. If the ignition switch is in the start position for more than 4 seconds without the engine cranking, the CKP diagnostics may fail and set this DTC.
- Insufficient fuel may cause this DTC to set.

CIRCUIT/SYSTEM VERIFICATION
Attempt to start the engine. Observe the CKP Active Counter with a scan tool.
- If the CKP Active Counter does not increment, continue with Circuit/System Testing.

CIRCUIT/SYSTEM TESTING
1. With the ignition OFF, disconnect the harness connector at the CKP sensor.
2. With the ignition ON, measure for 4.8-5.2 volts, between the 5-Volt reference circuit of the CKP sensor and ground.
- If the voltage is less than 4.8 volts, test for a short to ground, open/high resistance at the circuit, or faulty ECM.
3. With the ignition ON, measure for 4.8-5.2 volts between the 5-Volt reference circuit of the CKP sensor and the low reference circuit of the CKP sensor.
- If the voltage is less than 4.8 volts, test for an open/high resistance at the circuit or a faulty ECM.
4. With the ignition ON, momentarily connect a test lamp between the CKP sensor signal circuit and the 5-Volt reference circuit of the CKP sensor. The fuel pump should operate when the test lamp is applied to the CKP sensor signal circuit.
- If the fuel pump does not operate when the test lamp is applied to the CKP sensor signal circuit, test for a short to ground, open/high resistance, short to voltage at the circuit, or a faulty ECM.
5. Remove the CKP sensor.
6. 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
7. Inspect the CKP reluctor wheel for the following conditions:
- Physical damage
- Excessive end play or looseness
- Improper installation
8. 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 Verification Tests