DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM Dodge Ram Van B2500

Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see RAM VAN & RAM WAGON 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 PCM, defective CKP sensor, defective CMP sensor, defective connectors or defective wiring harness.

Scheme 28

Scheme 29

1. 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 5).
2. Start engine and allow it to idle. Wiggle wiring harness from CKP sensor and CMP sensor to PCM. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. For CKP sensor location (Scheme 28) For CMP sensor location (Scheme 29) If engine misses or stalls while wiggling wiring harness, repair wiring harness as necessary where wiggling caused engine to stall. Perform TEST VER-2A. If engine does not miss or stall while wiggling wiring harness, go to next step.
3. Start engine and allow it to idle. Using scan tool in lab scope mode, probe CKP sensor signal circuit (Gray/Black wire). With engine running, wiggle CKP sensor wiring harness and connectors. If lab scope pattern is steady, go to next step. If lab scope pattern is irregular, repair wiring harness or connectors as necessary where wiggling caused an irregular lab scope pattern. If connectors and wiring harness are okay, replace CKP sensor. Perform TEST VER-2A.
4. Turn ignition off. Connect lab scope to CMP sensor. Turn ignition on, with engine off. Check for CMP sensor pulses on lab scope. If CMP sensor does not generate pulses, replace CMP sensor. Perform TEST VER-2A. If CMP sensor generates pulses, see «INACTIVE DTC CONDITION»(ref-139160-S32382818132002042600000).
5. Turn ignition off. Disconnect CKP sensor connector. (Scheme 28) Clean and/or repair connector as necessary. 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 volts, go to next step. If voltage is 4 volts or less, go to step 11).
6. Ensure ignition is off. Ensure CKP sensor connector is still disconnected. Connect one end of a jumper wire to CKP sensor connector, signal circuit (Gray/Black wire). Turn ignition on, with engine off. Using scan tool, monitor current CKP count when tapping other end of jumper wire to sensor ground circuit (Black/Light Blue wire) several times. If CKP count changes, go to next step. If CKP count does not change, go to step 8).
7. Ensure ignition is off. Remove CKP sensor. (Scheme 28) Inspect flywheel for damage. If flywheel is damaged, repair as necessary. Perform TEST VER-2A. If flywheel is not damaged, replace CKP sensor. Perform TEST VER-2A.
8. Ensure ignition is off. Ensure CKP sensor connector is still disconnected. Connect one end of test light to 12-volt source. Touch other end of test light to sensor ground circuit (Black/Light Blue wire). If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair sensor ground circuit for open or high resistance. Perform TEST VER-2A.
9. 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. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance of CKP 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 CKP signal circuit for open or high resistance. Perform TEST VER-2A.
10. Ensure ignition is off. Ensure CKP sensor and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and CKP sensor, signal circuit (Gray/Black wire). If resistance is less than 5 ohms, repair signal circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, test all power and sensor ground circuits at PCM. Repair as necessary. If circuits are okay, replace PCM. Perform TEST VER-2A.
11. Turn ignition off. Ensure CKP sensor is still disconnected. Disconnect CMP sensor connector. For CMP sensor location (Scheme 29) Clean and/or repair connector as necessary. 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 volts, replace CMP sensor. Perform TEST VER-2A. If voltage is 4 volts or less, go to next step.
12. Turn ignition off. Ensure CKP sensor, CMP sensor and PCM connectors are still disconnected. Using an ohmmeter, check resistance between ground and CKP sensor connector, 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 CKP sensor 5-volt supply circuit for short to ground. Perform TEST VER-2A.
13. Turn ignition off. Ensure CKP sensor and PCM connectors are still disconnected. Using ohmmeter, check resistance of 5-volt supply circuit (Orange wire) between CKP sensor and PCM. If resistance is 5 ohms or more, repair open 5-volt supply circuit. Perform TEST VER-2A. If resistance is less than 5 ohms, test all power and sensor ground circuits at PCM. Repair as necessary. If circuits are okay, replace PCM. Perform TEST VER-2A.