Diagnostic Aids

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

• Crankshaft Position (CKP) sensor.
• CKP wiring harness or connector(s).
• Faulty Powertrain Control Module (PCM).

1. 1) Check CKP+ Circuit To PCM
   
   Turn ignition off. Disconnect scan tool from DLC. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Install Breakout Box (014-00950). Connect PCM to breakout box. Turn ignition on. Measure voltage between test pin No. 21 (CKP+) at breakout box and negative battery terminal. If voltage is not 1-2 volts, go to next step. If voltage is 1-2 volts, go to step 10).
2. 2) Check For CKP+ Voltage Fault
   
   Turn ignition off. Disconnect CKP sensor connector. Turn ignition on. Measure voltage between test pin No. 21 (CKP+) at breakout box and negative battery terminal. If voltage is more than one volt, but less than 2 volts, go to next step. If voltage is not as specified, go to step 18).
3. 3) Check For CKP- Voltage Fault
   
   Ensure ignition is on. Measure voltage between test pin No. 22 at breakout box and negative battery terminal. If voltage is 1-2 volts, replace CKP sensor. If voltage is not 1-2 volts, go to next step.
4. 4) Determine Fault
   
   If voltage reading in step 3) is less than one volt, go to next step. If voltage reading in step 3) is not less than one volt, go to step 6).
5. 5) Check CKP- Circuit For Short To Ground
   
   Turn ignition off. Disconnect PCM from breakout box. Measure resistance between breakout box test pin 22 and test pins No. 51 and 103 at breakout box. If both resistance readings are more than 10,000 ohms, replace PCM. If any resistance reading is less than 10,000 ohms, repair CKP- circuit short to ground.
6. 6) Check CKP- Sensor For Short To Power
   
   Turn ignition on. Measure voltage between breakout box test pins 22 and negative battery terminal. If voltage is .5 volt or more, repair CKP- circuit short to power. If resistance is less than .5 volt, replace PCM.
   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 6) to step 10). No test procedures have been omitted.
7. 10) Check CKP Sensor Voltage At PCM
   
   While cranking engine, measure voltage between test pins No. 21 and 22 at breakout box. If A/C voltage stabilized at more than .4 volt, CKP circuit is okay. Go to CIRCUIT TEST JB  . If voltage is .4 volt or less, go to next step.
8. 11) Check CKP Sensor Voltage At PCM
   
   Disconnect PCM 104-pin connector. While cranking engine, measure voltage between test pins No. 21 and 22 at breakout box. If A/C voltage stabilized at more than .4 volt, replace PCM. If voltage is .4 volt or less, go to next step.
9. 12) Check CKP Circuit Resistance
   
   Turn ignition off. Measure resistance between test pins No. 21 and 22 at breakout box. If resistance is 300-800 ohms, go to step 16). If resistance is not 300-800 ohms, go to next step.
10. 13) Determine Fault
    
    If resistance is less than 300 ohms in step 12), go to step 17). If resistance is not less than 300 ohms in step 12). go to next step.
11. 14) Check For Open Circuit
    
    Disconnect CKP sensor connector. Measure resistance between test pin No. 21 at breakout box and CKP+ terminal at CKP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in CKP+ circuit.
12. 15) Check For Open Circuit
    
    Measure resistance between test pin No. 22 at breakout box and CKP- terminal at CKP sensor wiring harness connector. If resistance is less than 5 ohms, replace CKP sensor. If resistance is 5 ohms or more, repair open in CKP- circuit.
13. 16) Check CKP Sensor & Trigger Wheel
    
    Check CKP sensor and trigger wheel for damage. Repair as necessary. If CKP sensor and trigger wheel are not damaged, replace CKP sensor.
14. 17) Check CKP+ Circuit For Short To CKP- Circuit
    
    Disconnect CKP sensor connector. Measure resistance between test pins No. 21 and 22 at breakout box. If resistance is more than 10,000 ohms, replace CKP sensor. If resistance is 10,000 ohms or less, CKP+ circuit is shorted to CKP- circuit. Repair as necessary.
15. 18) Determine Fault
    
    If voltage reading in step 2) is less than one volt, go to next step. If voltage reading in step 3) is not less than one volt, go to step 20).
16. 19) Check CKP+ Circuit For Short To Ground
    
    Turn ignition off. Disconnect PCM from breakout box. Measure resistance between breakout box test pin 21 and test pins No. 51 and 103 at breakout box. If both resistance readings are more than 10,000 ohms, replace PCM. If any resistance reading is less than 10,000 ohms, repair CKP+ circuit short to ground.
17. 20) Check CKP+ Sensor For Short To Power
    
    Turn ignition on. Measure voltage between breakout box test pins 21 and negative battery terminal. If voltage is .5 volt or more, repair CKP+ circuit short to power. If resistance is less than .5 volt, replace PCM.