Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
Note. DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM is monitored during engine cranking. DTC may be stored in Powertrain Control Module (PCM) when PCM senses no Crankshaft Position (CKP) sensor signal during engine cranking, and at least 3 Camshaft Position (CMP) sensor signals have occurred. Possible causes are: defective distributor, defective pulse ring, defective PCM, defective CKP sensor, defective CMP sensor, defective connectors or defective wiring.
- Turn ignition on, with engine off. Using scan tool, read current CKP count and attempt to start engine. If current CKP count changes while attempting to start engine, go to next step. If current CKP count does not change while attempting to start engine, go to step 4).
- Turn ignition off. Visually inspect related connectors and wiring harness. Repair connectors and wiring harness as necessary. Perform TEST VER-2A. If connectors and wiring harness are okay, go to next step.
- Start engine and allow it to idle. Wiggle wiring harness from CKP sensor to PCM. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. For CKP sensor location (Scheme 28) If engine stalls while wiggling wiring harness, repair wiring harness as necessary where wiggling caused engine to stall. Perform TEST VER-2A. If engine does not stall while wiggling wiring harness, test is complete.
- Turn engine off. Disconnect CKP sensor connector. (Scheme 28) Clean and/or repair connector as necessary. Visually inspect connector for corroded, damaged, pushed-out or miswired terminals. Repair connector as necessary. Perform TEST VER-2A. If connector is okay, go to next step.
- Ensure ignition is off. Ensure CKP sensor connector is still disconnected. Turn ignition on, with engine off. Using a voltmeter, check voltage on CKP sensor connector, 5-volt supply circuit (Orange wire). If voltage is more than 4.5 volts, go to next step. If voltage is 4.5 volts or less, go to step 11).
- Ensure ignition is off. Ensure CKP sensor connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Visually inspect connectors for corroded, damaged, pushed-out or miswired terminals. Repair connectors as necessary. Perform TEST VER-2A. If connectors are okay, go to next step.
- Ensure ignition is off. Ensure CKP sensor and PCM connectors are still disconnected. Using an ohmmeter, check resistance between ground and CKP sensor connector, sensor ground circuit (Brown/Yellow wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open sensor ground circuit. Perform TEST VER-2A.
- Ensure ignition is off. Ensure CKP sensor and PCM connectors are still disconnected. Using ohmmeter, check resistance of CKP sensor signal circuit (Gray/Black wire) between CKP sensor and PCM. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open signal circuit. Perform TEST VER-2A.
- Ensure ignition is off. Ensure CKP sensor and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, CKP sensor signal circuit (Gray/Black wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair signal circuit for short to ground. Perform TEST VER-2A.
- At this time, CKP sensor is assumed to be defective. Replace CKP sensor. Perform TEST VER-2A.
- Ensure ignition is off. Ensure CKP sensor is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Visually inspect PCM connectors for corroded, damaged, pushed-out or miswired terminals. Repair connectors as necessary. Perform TEST VER-2A. If connectors are okay, go to next step.
- Ensure ignition is off. Ensure CKP sensor and PCM connectors are still disconnected. Using an ohmmeter, check resistance of CKP sensor 5-volt supply circuit (Orange wire) between CKP sensor and PCM. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open CKP sensor 5-volt supply circuit. Perform TEST VER-2A.
- Ensure ignition is off. Ensure CKP sensor and PCM connector are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, CKP sensor 5-volt supply circuit (Orange wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair sensor 5-volt supply circuit for short to ground. Perform TEST VER-2A.
- At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-2A.
