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 engine 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) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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. |
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 | Attempt to start the engine. Does the engine start and run? | -- | Go to Intermittent Conditions | Go to Step 3 | ||||||||||||||
3 |
Is the voltage within the specified value? | B+ | Go to Step 4 | Go to Step 8 | ||||||||||||||
4 | Measure the voltage from the 12-volt reference to the low reference of the CKP sensor with a DMM. Is the voltage within the specified value? | B+ | 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 more than the specified value? | 1 V | Go to Step 9 | Go to Step 6 | ||||||||||||||
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 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | ||||||||||||||
14 | Inspect the CKP reluctor wheel for the following conditions:
Refer to Crankshaft Reluctor and Oil Pump Drive Gear Replacement in Engine Mechanical-6.6L. 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 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 18 | ||||||||||||||
18 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||||||
