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DTC P0320: No Crank Reference Signal At Pcm: Testing

  1. Turn ignition on. Using scan tool, read current CKP state while cranking engine. If scan tool displays current CKP state PRESENT, go to next step. If scan tool does not display current CKP state PRESENT, go to step  6 .
    NOTE: The following step checks for any pulses generated on lab scope by the CKP sensor. With ignition on, no CKP sensor pulses should be generated.
  2. Backprobe lab scope lead to terminal No. 8 (Gray/Black wire) at PCM C1 harness connector. See Figure . PCM is located in engine compartment on left front fender, near radiator support. Observe lab scope screen and turn ignition on. If any pulses were generated when ignition was turned on, replace CKP sensor. If no pulses were generated, go to next step.
    NOTE: The following step checks for any pulses generated on lab scope by the CMP sensor. With ignition on, no CMP sensor pulses should be generated.
  3. Turn ignition off. Disconnect lab scope. Backprobe lab scope lead to terminal No. 18 (Tan/Yellow wire) at PCM C1 harness connector. See Figure . Observe lab scope screen and turn ignition on. If any pulses were generated when ignition was turned on, replace CMP sensor. If no pulses were generated, go to next step.
  4. Turn ignition off. Backprobe lab scope lead to terminal No. 8 (Gray/Black wire) at PCM C1 harness connector. See Figure . Observe lab scope screen and start engine. Wiggle wiring harness from CKP sensor to PCM while observing lab scope pattern. CKP sensor is mounted to left side of transmission bellhousing. If any irregularities in lab scope pattern occurs while wiggling wiring harness, check wiring harness where wiggling caused irregularity in lab scope pattern. Repair wiring as necessary. If wiring harness is okay, replace CKP sensor. If there are no irregularities in lab scope pattern while wiggling wiring harness, go to next step.
  5. At this time, conditions for DTC to set do not exist or fault is an intermittent problem. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Using scan tool, monitor parameters related to DTC while wiggling connectors and wiring harness. If value changes while wiggling connectors and wiring harness, repair connectors and wiring harness where wiggling caused value to change. If value does not change, review FREEZE FRAME data using scan tool. Attempt to duplicate condition that caused DTC to set. Check for any related technical service bulletins that may apply. Visually inspect related connectors and wiring harness. Repair connectors and wiring harness as necessary. See WIRING DIAGRAMS article. If no problems are indicated, test is complete.
  6. Turn ignition off. Disconnect CKP sensor connector. CKP sensor is mounted to left side of transmission bellhousing. CKP sensor connector is located on top of intake manifold, near firewall. Turn ignition on. Measure voltage between ground and Orange wire at CKP sensor harness connector. If voltage is 4.5-5.0 volts, go to next step. If voltage is not 4.5-5.0 volts, go to step  15 .
  7. Measure voltage between ground and Gray/Black wire at CKP sensor harness connector. If voltage is 4.5-5.0 volts, go to next step. If voltage is not 4.5-5.0 volts, go to step  10 .
  8. Turn ignition off. Measure resistance between ground and Brown/Yellow wire at CKP sensor harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Brown/Yellow wire.
  9. Turn ignition off. Remove CKP sensor. Inspect notches on flywheel/drive plate for damage or debris. Flywheel/drive plate contains 3 sets of notches which contain 4 slots in each set. Check slotted areas for damage or any foreign debris. If slotted areas on flywheel/drive plate are okay and no debris exists, replace CKP sensor. If slotted areas on flywheel/drive plate are damaged or debris exists, repair or replace flywheel/drive plate as necessary.
  10. Turn ignition off. Ensure CKP sensor connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment on left front fender, near radiator support. Visually inspect connectors for corroded, damaged, pushed-out or miswired terminals. Repair connectors as necessary. If connectors are okay, measure resistance between ground and Gray/Black wire at CKP harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray/Black wire between CKP sensor and PCM.
  11. Measure resistance of Gray/Black wire between CKP harness connector and terminal No. 8 at PCM C1 harness connector. See Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Black wire.
  12. Ensure ignition is off. Reconnect PCM connectors. Turn ignition on. Measure voltage between ground and Gray/Black wire at CKP sensor harness connector. If voltage is 5 volts or less, go to next step. If voltage is more than 5 volts, repair short to voltage in Gray/Black wire between CKP sensor and PCM.
  13. Turn ignition off. Disconnect PCM connectors. Ensure CKP sensor is still disconnected. Measure resistance between Orange and Gray/Black wires at CKP sensor harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, Orange and Gray/Black wires are shorted together. Repair wiring as necessary.
  14. At this time, PCM is assumed to be defective. Replace PCM.
  15. Turn ignition off. Disconnect PCM connectors. Measure resistance between ground and Orange wire at CKP harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Orange wire between PCM and CKP sensor.
  16. Measure resistance of Orange wire between CKP sensor harness connector and terminal No. 17 at PCM C1 harness connector. See Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Orange wire.
  17. Ensure ignition is off. Reconnect PCM connectors. Turn ignition on. Measure voltage between ground and Orange wire at CKP sensor harness connector. If voltage is 5.5 volts or less, go to next step. If voltage is more than 5.5 volts, repair short to voltage in Orange wire between CKP sensor and PCM.
  18. At this time, PCM is assumed to be defective. Replace PCM.
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