The crankshaft position (CKP) sensor is a 24X sensor. It provides 24 digital ON/OFF signals to the powertrain control module (PCM) per revolution of the crankshaft. This information is used by the PCM for ignition timing, fuel injector timing, misfire diagnostics, and tachometer display. The PCM supplies 12 volts to the sensor on the 12-volt reference circuit, and provides a ground on the low reference circuit. The CKP sensor provides signals to the PCM on the medium resolution engine speed signal circuit.
A faulty CKP sensor, CMP sensor, or a short to ground on either 12-volt reference circuit may cause the CKP signal to be lost, preventing the engine from running.
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||||||
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Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | ||||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||
2 | Crank the engine. Does the engine start and run? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||||||||
3 |
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 4 | ||||||||||||
4 |
Is the voltage measured within 1 volt of the specified value? | B+ | Go to Step 7 | Go to Step 5 | ||||||||||||
5 |
Does the voltage change? | -- | Go to Step 19 | Go to Step 6 | ||||||||||||
6 | Measure the voltage from the 12-volt reference circuit of the CMP sensor to a good ground with a DMM. Is the voltage measured within 1 volt of the specified value? | B+ | Go to Step 12 | Go to Step 11 | ||||||||||||
7 | Measure the voltage from the 12-volt reference circuit to the low reference circuit of the CKP sensor with a DMM. Is the voltage measured within 1 volt of the specified value? | B+ | Go to Step 8 | Go to Step 13 | ||||||||||||
8 |
Does the test lamp illuminate? | -- | Go to Step 14 | Go to Step 9 | ||||||||||||
Does the RPM change? | -- | Go to Step 10 | Go to Step 15 | |||||||||||||
10 |
Does the DMM display the specified value? | OL | Go to Step 16 | Go to Testing for Intermittent Conditions and Poor Connections | ||||||||||||
11 | Test the 12-volt reference circuit of the CKP sensor and the CMP sensor for a short to ground. Refer to Circuit Testing. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 | ||||||||||||
12 | Test the 12-volt reference circuit of the CKP sensor for an open. Refer to Circuit Testing. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 18 | ||||||||||||
13 | Test the low reference circuit of the CKP sensor for an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 18 | ||||||||||||
14 | Test the medium resolution engine speed signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 | ||||||||||||
15 | Test the medium resolution engine speed signal circuit for an open or for a short to voltage. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 18 | ||||||||||||
16 |
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 17 | ||||||||||||
17 | Inspect the reluctor wheel for the following conditions:
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 20 | ||||||||||||
18 | Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 | ||||||||||||
19 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement. Did you complete the replacement? | -- | Go to Step 22 | -- | ||||||||||||
20 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement. Did you complete the replacement? | -- | Go to Step 22 | -- | ||||||||||||
21 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 22 | -- | ||||||||||||
22 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 23 | ||||||||||||
23 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |