The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces a DC voltage of varying amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the DC output voltage depends on crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58-tooth reluctor wheel attached to the crankshaft. The engine control module (ECM) determines the crankshaft position by the reference gap. The ECM can synchronize the ignition timing, fuel injector timing, and the spark knock control based on the CKP sensor and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect a misfire. The CKP sensor circuits connect directly to the ECM. The circuits between the CKP sensor and the ECM consists of the following:
• | A 12-volt reference |
• | A low reference |
• | A CKP sensor signal |
If the ECM detects no CKP sensor signal, DTC P0335 sets.
• | DTCs P0340, P0341, P0345, P0346 are not set. |
• | The engine is cranking or running. |
The ECM does not detect a signal from the CKP sensor.
• | 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. |
Step | Action | Values | Yes | No | ||||||||||||
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Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module 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 Step 4 | Go to Step 3 | ||||||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||||||
4 |
Is the voltage within the specified value? | B+ | Go to Step 5 | Go to Step 7 | ||||||||||||
5 | Measure the voltage from the 12-volt reference circuit to the low reference circuit of the CKP sensor on the ECM side of the 12-way connector with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage within the specified value? | B+ | Go to Step 6 | Go to Step 8 | ||||||||||||
6 |
Is the voltage within the specified range? | 8-11 V | Go to Step 10 | Go to Step 9 | ||||||||||||
7 | Test the 12-volt reference circuit for an open and a short to ground between the ECM and the 12-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 14 | ||||||||||||
8 | Test the low reference circuit for an open or short to ground between the ECM and the 12-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 14 | ||||||||||||
9 | Test the CKP sensor signal circuit between the ECM and the 12-way connector for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 14 | ||||||||||||
10 | Test the following circuits of the CKP sensor for high resistance between the ECM and the 12-way connector.
Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 11 | ||||||||||||
11 |
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 12 | ||||||||||||
12 | Test the low reference circuit between the 12-way connector and the CKP sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 13 | ||||||||||||
13 | Test the CKP sensor signal circuit between the 12-way connector and the CKP sensor for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 16 | ||||||||||||
14 | Test for an intermittent and for a poor connection at the ECM side of the 12-way connector. 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 22 | Go to Step 15 | ||||||||||||
15 | Test for an intermittent and for a poor connection 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 22 | Go to Step 21 | ||||||||||||
16 | Test for an intermittent and for a poor connection at the CKP sensor side of the 12-way connector. 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 22 | Go to Step 17 | ||||||||||||
17 | Test for an intermittent and for a poor connection 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 22 | Go to Step 18 | ||||||||||||
18 |
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 | ||||||||||||
19 | Inspect the crankshaft reluctor wheel for following conditions:
Refer to Crankshaft and Bearing Cleaning and Inspection in Engine Mechanical. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 20 | ||||||||||||
20 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- | ||||||||||||
21 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- | ||||||||||||
22 |
Did the DTC fail this ignition? | -- | Go to Step 23 | Go to Step 2 | ||||||||||||
23 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |