The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor works in conjunction with a 58-rib reluctor ring attached to the crankshaft in which two ribs are missing, 60 minus 2 ring. The engine control module (ECM) synchronizes the crankshaft position by the reference gap which is created by the two missing ribs. The CKP sensor circuits are connected directly to the ECM. The circuits between the CKP sensor and the ECM consists of the following:
• | A CKP sensor high |
• | A CKP sensor low |
• | A shielded ground |
If the ECM has detected less than 58 reference pulses, DTC P0337 sets.
• | The engine is cranking or running. |
• | DTCs P0341, P0342, P0343 are not set. |
The ECM has detected less than 58 CKP reference pulses.
• | 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. |
• | 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. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for resistance of the CKP sensor and its lead.
This step inspects for electromagnetic interference in any of the CKP circuits.
Step | Action | Values | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||||||
2 |
Important: If DTC P0335 sets, diagnose this DTC first. Attempt to start the engine. Does the engine start and run? | -- | Go to Step 3 | Go to Step 4 | ||||||||||||
3 |
Does the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||||||
Inspect all of the circuits going to the CKP sensor for the following:
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 5 | |||||||||||||
Is the resistance within the specified range? | 700-1100 ohms | Go to Step 9 | Go to Step 6 | |||||||||||||
6 | Test the CKP Sensor High Circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 7 | |||||||||||||
7 | Inspect for poor connections at the CKP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 | ||||||||||||
8 | Inspect for poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 | ||||||||||||
9 |
Important: If the sensor lead is damaged in any way, DO NOT repair the lead.
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||||||||||
10 | Inspect the reluctor ring for the following conditions:
Refer to Diagnostic Aids and Crankshaft and Bearing Removal in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 | ||||||||||||
11 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||||||||||
12 | Replace the ECM. Refer to Engine Control Module Replacement . Did you find and correct the condition? | -- | Go to Step 13 | -- | ||||||||||||
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 | ||||||||||||
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |