DTC 21: Crankshaft Position Sensor System: Diagnosis

Required Special Tool: 

• MB991502: Scan Tool (MUT-II)

1. STEP 1. Using scan tool MB991502, check data list item 21: Crankshaft Position Sensor. 
   CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
   1. Connect scan tool MB991502 to the data link connector.
   2. With the gear selector lever in the "P" position, start the engine and run at idle.
   3. Set scan tool MB991502 to data reading mode for item 21, Crankshaft Position Sensor.
      • When the accelerator pedal is not depressed (throttle valve is fully closed) the display on the scan tool MB991502 should be "600 to 900 r/min."
      • With the accelerator pedal depressed, the engine speed display on the scan tool MB991502 should increase according to engine speed.
        Fig 1: Connecting Scan Tool MB991502 To Data Link Connector

        Courtesy of CHRYSLER CORP.

   Q: Does the engine speed display increase according to engine speed when the accelerator pedal is depressed? 

   YES  : It can be assumed that this malfunction is intermittent. Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS .

   NO:  Go to Step 2.

2. STEP 2. Using the oscilloscope, check the waveform at crankshaft position sensor connector B-20. 
   1. Do not disconnect connector B-20.
      Fig 2: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

      Courtesy of CHRYSLER CORP.
      Fig 3: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

      Courtesy of CHRYSLER CORP.
   2. Connect an oscilloscope probe between crankshaft position sensor connector B-20 terminal 2 and ground by backprobing.
   3. With the gear selector lever in the "P" position, start the engine and run at idle.
      Fig 4: Connecting Oscilloscope Probe Between Crankshaft Position Sensor Connector B-20 Terminal 2 And Ground

      Courtesy of CHRYSLER CORP.
   4. Check the waveform.
      • The waveform should show a pattern similar to the illustration. The maximum value should be 4.8 volts or more and the minimum value 0.6 volt or less. The output waveform should not contain electrical noise.
   5. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the waveform normal? 

   YES  : Go to Step 3.

   NO:  Go to  Step 5.

   Fig 5: Identifying Normal Waveform Pattern

   Courtesy of CHRYSLER CORP.
3. STEP 3. Check crankshaft position sensor connector B-20 and PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connectors and terminals in good condition? 

   YES  : Go to Step 4.

   NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

   Fig 6: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

   Courtesy of CHRYSLER CORP.
   Fig 7: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

   Courtesy of CHRYSLER CORP.
   Fig 8: Identifying PCM Connector C-114 Or C-115

   Courtesy of CHRYSLER CORP.
4. STEP 4. Using scan tool MB991502, check data list item 21: Crankshaft Position Sensor. 
   CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
   1. Connect scan tool MB991502 to the data link connector.
   2. With the gear selector lever in the "P" position, start the engine and run at idle.
   3. Set scan tool MB991502 to data reading mode for item 21, Crankshaft Position Sensor.
      • When the accelerator pedal is not depressed (throttle valve is fully closed) the display on the scan tool MB991502 should be "600 to 900 r/min."
      • With the accelerator pedal depressed, the engine speed display on the scan tool MB991502 should increase according to engine speed.

   Q: Does the engine speed display increase according to engine speed when the accelerator pedal is depressed? 

   YES  : It can be assumed that this malfunction is intermittent. Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS .

   NO:  Replace the PCM.

   Fig 9: Connecting Scan Tool MB991502 To Data Link Connector

   Courtesy of CHRYSLER CORP.
5. STEP 5. Check crankshaft position sensor connector B-20 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connector and terminals in good condition? 

   YES  : Go to Step 6.

   NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

   Fig 10: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

   Courtesy of CHRYSLER CORP.
   Fig 11: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

   Courtesy of CHRYSLER CORP.
6. STEP 6. Measure the sensor output voltage at crankshaft position sensor connector B-20. 
   1. Disconnect connector B-20 and measure at the harness side.
   2. Turn the ignition switch to the "ON" position.
      Fig 12: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

      Courtesy of CHRYSLER CORP.
      Fig 13: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

      Courtesy of CHRYSLER CORP.
   3. Measure the voltage between terminal 2 and ground.
      • The voltage should measure between 4.9 and 5.1 volts.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the measured voltage between 4.9 and 5.1 volts? 

   YES  : Go to  Step 12.

   NO:  Go to Step 7.

   Fig 14: Measuring Voltage Between Terminal 2 And Ground

   Courtesy of CHRYSLER CORP.
7. STEP 7. Measure the sensor output voltage at PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > by backprobing. 
   1. Do not disconnect connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine >.
   2. Disconnect connector B-20 at the crankshaft position sensor.
   3. Turn the ignition switch to the "ON" position.
      Fig 15: Locating PCM Connector C-114 Or C-115

      Courtesy of CHRYSLER CORP.
   4. Measure the voltage between terminal 45 and ground by backprobing.
      • Voltage should measure between 4.9 and 5.1 volts.
   5. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the measured voltage between 4.9 and 5.1 volts? 

   YES  : Go to Step 8.

   NO:  Go to  Step 10.

   Fig 16: Measuring Voltage Between Terminal 45 And Ground

   Courtesy of CHRYSLER CORP.
8. STEP 8. Check PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are the connector and terminals in good condition? 

   YES  : Go to Step 9.

   NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

   Fig 17: Locating PCM Connector C-114 Or C-115

   Courtesy of CHRYSLER CORP.
9. STEP 9. Check the harness for open circuit between crankshaft position sensor connector B-20 terminal 2 and PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > terminal 45. 

   Q: Is the harness wire in good condition? 

   YES  : Go to  Step 4.

   NO:  Repair or replace the harness wire.

   Fig 18: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

   Courtesy of CHRYSLER CORP.
   Fig 19: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

   Courtesy of CHRYSLER CORP.
   Fig 20: Identifying PCM Connector C-114 Or C-115

   Courtesy of CHRYSLER CORP.
10. STEP 10. Check PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Are the connector and terminals in good condition? 

    YES  : Go to Step 11.

    NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

    Fig 21: Locating PCM Connector C-114 Or C-115

    Courtesy of CHRYSLER CORP.
11. STEP 11. Check the harness for a short circuit to ground between crankshaft position sensor connector B-20 terminal 2 and PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > terminal 45. 

    Q: Is the harness wire in good condition? 

    YES  : Go to  Step 4.

    NO:  Repair or replace the harness wire.

    Fig 22: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 23: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 24: Identifying PCM Connector C-114 Or C-115

    Courtesy of CHRYSLER CORP.
12. STEP 12. Measure the power supply voltage at crankshaft position sensor connector B-20. 
    1. Disconnect connector B-20 and measure at the harness side.
    2. Turn the ignition switch to the "ON" position.
       Fig 25: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

       Courtesy of CHRYSLER CORP.
       Fig 26: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

       Courtesy of CHRYSLER CORP.
    3. Measure the voltage between terminal 3 and ground.
       • The voltage should measure battery positive voltage.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage battery positive voltage? 

    YES  : Go to  Step 15.

    NO:  Go to Step 13.

    Fig 27: Measuring Voltage Between Terminal 3 And Ground

    Courtesy of CHRYSLER CORP.
13. STEP 13. Check MFI relay connector A-18X in the engine component relay box for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Are the connector and terminals in good condition? 

    YES  : Go to Step 14.

    NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

    Fig 28: Locating MFI Relay Connector A-18X

    Courtesy of CHRYSLER CORP.
14. STEP 14. Check the harness for open circuit or short circuit to ground between MFI relay connector A-18X terminal 4 in the engine component relay box and crankshaft position sensor connector B-20 terminal 3. 

    Q: Is the harness wire in good condition? 

    YES  : Go to  Step 4.

    NO:  Repair or replace the harness wire.

    Fig 29: Identifying MFI Relay Connector A-18X

    Courtesy of CHRYSLER CORP.
    Fig 30: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 31: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
15. STEP 15. Measure the resistance of the ground circuit at crankshaft position sensor connector B-20. 
    1. Disconnect connector B-20 and measure at the harness side.
       Fig 32: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

       Courtesy of CHRYSLER CORP.
       Fig 33: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

       Courtesy of CHRYSLER CORP.
    2. Measure the resistance between terminal 1 and ground.
       • The resistance should measure less than 2 ohms.

    Q: Is the resistance less than 2 ohms? 

    YES  : Go to  Step 21.

    NO:  Go to Step 16.

    Fig 34: Measuring Resistance Between Terminal 1 And Ground

    Courtesy of CHRYSLER CORP.
16. STEP 16. Measure the ground voltage at PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > by backprobing. 
    1. Do not disconnect connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine >.
    2. Turn the ignition switch to the "ON" position.
       Fig 35: Identifying PCM Connector C-110 Or C-112

       Courtesy of CHRYSLER CORP.
    3. Measure the voltage between terminal 16 and ground by backprobing.
       • The voltage should measure 0.5 volt or less.
    4. Turn the ignition switch to the "LOCK" (OFF) position.

    Q: Is the measured voltage 0.5 volt or less? 

    YES  : Go to Step 17.

    NO:  Go to  Step 19.

    Fig 36: Measuring Voltage Between Terminal 16 And Ground

    Courtesy of CHRYSLER CORP.
17. STEP 17. Check PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Are the connector and terminals in good condition? 

    YES  : Go to Step 18.

    NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

    Fig 37: Identifying PCM Connector C-110 Or C-112

    Courtesy of CHRYSLER CORP.
18. STEP 18. Check the harness for open circuit or damage between crankshaft position sensor connector B-20 terminal 1 and PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > terminal 16. 

    Q: Is the harness wire in good condition? 

    YES  : Go to  Step 4.

    NO:  Repair or replace the harness wire.

    Fig 38: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 39: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 40: Identifying PCM Connector C-110 Or C-112

    Courtesy of CHRYSLER CORP.
19. STEP 19. Check PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Are the connector and terminals in good condition? 

    YES  : Go to Step 20.

    NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

    Fig 41: Locating PCM Connector C-110 Or C-112

    Courtesy of CHRYSLER CORP.
20. STEP 20. Check the harness for a short circuit to ground between crankshaft position sensor connector B-20 terminal 1 and PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > terminal 16. 

    Q: Is the harness wire in good condition? 

    YES  : Go to  Step 4.

    NO:  Repair or replace the harness wire.

    Fig 42: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 43: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 44: Locating PCM Connector C-110 Or C-112

    Courtesy of CHRYSLER CORP.
21. STEP 21. Check PCM connectors C-110 < 2.4L Engine > or C-112 < 3.0L Engine > and C-114 < 2.4L Engine > or C-115 < 3.0L Engine >, and MFI relay connector A-18X for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Are the connectors and terminals in good condition? 

    YES  : Go to Step 22.

    NO:  Repair or replace the damaged components. Refer to HARNESS CONNECTOR INSPECTION .

    Fig 45: Identifying PCM Connectors C-110 Or C-112 And C-114 Or C-115

    Courtesy of CHRYSLER CORP.
    Fig 46: Identifying MFI Relay Connector A-18X

    Courtesy of CHRYSLER CORP.
22. STEP 22. Check the harness for damage between crankshaft position sensor connector B-20 terminal 1 and PCM connector C-110 < 2.4L Engine > or C-112 < 3.0L Engine > terminal 16. 

    Q: Is the harness wire in good condition? 

    YES  : Go to Step 23.

    NO:  Repair or replace the harness wire.

    Fig 47: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 48: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 49: Identifying PCM Connector C-110 Or C-112

    Courtesy of CHRYSLER CORP.
23. STEP 23. Check the harness for damage between crankshaft position sensor connector B-20 terminal 2 and PCM connector C-114 < 2.4L Engine > or C-115 < 3.0L Engine > terminal 45. 

    Q: Is the harness wire in good condition? 

    YES  : Go to Step 24.

    NO:  Repair or replace the harness wire.

    Fig 50: Locating Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 51: Locating Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 52: Locating PCM Connector C-114 Or C-115

    Courtesy of CHRYSLER CORP.
24. STEP 24. Check the harness for damage between MFI relay connector A-18X terminal 4 in the engine component relay box and crankshaft position sensor connector B-20 terminal 3. 

    Q: Is the harness wire in good condition? 

    YES  : Go to Step 25.

    NO:  Repair or replace the harness wire.

    Fig 53: Locating MFI Relay Connector A-18X

    Courtesy of CHRYSLER CORP.
    Fig 54: Identifying Crankshaft Position Sensor Connector B-20 (2.4L Engine)

    Courtesy of CHRYSLER CORP.
    Fig 55: Identifying Crankshaft Position Sensor Connector B-20 (3.0L Engine)

    Courtesy of CHRYSLER CORP.
25. STEP 25. Check the crankshaft angle sensing blade. 

    Q: Is the crankshaft angle sensing blade in good condition? 

    YES  : Replace the crankshaft position sensor. Refer to Ignition System - CRANKSHAFT POSITION SENSOR REMOVAL AND INSTALLATION .

    NO:  Replace the crankshaft angle sensing blade.