Circuit Description
The hall effect crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. There are 57 teeth on the front of the crankshaft sprocket, plus a sync gap. The CKP sensor will output an ON-OFF pulse as each window passes the sensing element. The CKP sensor is connected directly to the electronic control module (ECM) by the following circuits:
| • | The 12- volt reference circuit. |
| • | The low reference circuit. |
| • | The CKP sensor signal circuit. |
Conditions for Running the DTC
| • | The engine is cranking or running. |
| • | The camshaft position (CMP) sensor signal is present. |
Conditions for Setting the DTC
The engine control module (ECM) determines no signal from the CKP sensor for less than 8 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
Important:
• Remove any debris from the ECM connector surfaces before servicing the ECM. Inspect the ECM connector gaskets when diagnosing or replacing the ECM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the
ECM. • For any test that requires probing the ECM or the component harness connectors, use the
J 35616
Connector Test Adapter Kit. Using this kit prevents any damage to the harness connector terminals.
Refer to
Testing for Intermittent Conditions and Poor Connections
in Wiring Systems.
The following conditions may cause this DTC to set:
| • | Any poor connections or poor terminal tension at the sensor. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Any crankshaft reluctor wheel damage or improper installation |
| • | The sensor coming in contact with the reluctor wheel |
| • | The engine running out of fuel |
Excess crankshaft end play causes the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following conditions:
| • | A no start. |
| • | A start and stall. |
| • | Erratic performance. |
For an intermittent, refer to Intermittent Conditions .
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 | Attempt to start the engine. Does the engine start and run? | -- | Go to Diagnostic Aids | Go to Step 3 |
3 |
Does the DMM display a reading above the specified value? | 10 V | Go to Step 4 | Go to Step 8 |
4 | Connect a DMM between the 12- volt reference and the low reference circuit of the CKP Sensor. Does the DMM display a reading above the specified value? | 10 V | Go to Step 5 | Go to Step 7 |
5 | Connect a DMM between the CKP sensor signal and a good ground. Does the DMM display the specified value? | 0 V | Go to Step 6 | Go to Step 9 |
6 |
Does the DMM display a DC duty cycle within the specified value? | 45-55% | Go to Step 12 | Go to Step 10 |
7 | Test the low reference circuit for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 12 |
8 | Test the 12-volt reference circuit for an open or a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 12 |
9 | Test the CKP signal circuit for a short to voltage or a short to the 12-volt reference circuit. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 |
10 | Test the CKP signal circuit for an open or a short to ground. Refer to Testing for Continuity , Testing for Short to Ground , and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 |
11 | Check for poor connections at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 |
12 | Check for poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 |
13 | Inspect the CKP sensor for damage or looseness. Refer to Crankshaft Position Sensor Replacement . Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
14 | Inspect the CKP reluctor wheel for damage or looseness. Refer to Crankshaft Reluctor and Oil Pump Drive Gear Replacement in Engine Mechanical. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 |
15 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
16 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
17 |
Does the DTC run and pass? | -- | Go to Step 17 | -- |
18 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
