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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 39 (Engine Controls - Tests W/Codes - 5.2L CNG) >> Self-Diagnostic Tests >> Test TC-3A - No Cam Signal At Pcm (DTC 54)

Test TC-3A - No Cam Signal At Pcm (DTC 54)

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, and 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
  1. Using scan tool, erase DTCs. Attempt to start engine. If necessary, crank engine for up to 10 seconds. Using scan tool, read DTCs. Record scan tool DTCs. If scan tool displays NO CAM SYNC SIGNAL AT PCM, go to step 6).
  2. If scan tool does not display NO CAM SYNC SIGNAL AT PCM, condition required to set DTC is not present at this time. NO CAM SYNC SIGNAL AT PCM DTC sets if Powertrain Control Module (PCM) does not see a cam signal with crank signal present.
  3. Possible causes are: open or shorted 8-volt power supply circuit (Orange wire) to Camshaft Position (CMP) sensor, open or shorted CMP sensor signal circuit (Tan/Yellow wire), open sensor ground circuit (Black/Light Blue wire), improperly adjusted sensor, failed sensor, or failed PCM. Go to next step.
  4. Inspect all related wiring and connectors, and repair as necessary. Perform TEST VER-2. If wiring and connectors are okay, condition that initially set DTC has just been simulated. Perform following additional checks to assist in identifying a possible intermittent problem.
  5. Visually inspect related wiring harness connectors for broken, bent, pushed-out or corroded terminals. Visually inspect related wiring harnesses for chafed, pierced or broken wires. Check all related Tech Service Bulletins (TSBs) and perform corrective action as necessary. Test is complete. Perform TEST VER-2.
  6. Turn ignition off. Disconnect Camshaft Position (CMP) sensor connector. Using scan tool in voltmeter mode, check voltage on CMP sensor connector, 8-volt power supply circuit (Orange wire). If voltage is less than 7 volts, repair open Orange wire. Perform TEST VER-2.
  7. If voltage is more than 7 volts, connect a jumper wire to CMP sensor connector, CMP sensor signal circuit (Tan/Yellow wire). Tap other lead of jumper to CMP sensor connector, sensor ground circuit (Black/Light Blue wire). Without turning ignition switch to OFF position, attempt to start engine.
  8. If engine starts, replace CMP sensor. Perform TEST VER-2. If engine does not start, turn ignition off. Go to next step.
    NOTE: Following step will require help of an assistant.
  9. If resistance is less than 5 ohms, remove distributor cap. Observe rotor while an assistant cranks engine. If rotor does not turn, repair distributor as necessary. Perform TEST VER-2.
  10. If rotor turns, turn ignition off. Using scan tool in ohmmeter mode, check resistance of CMP sensor connector, sensor ground circuit (Black/Light Blue wire). If resistance is more than 5 ohms, repair open in Black/Light Blue wire. Perform TEST VER-2.
  11. If resistance is less than 5 ohms, disconnect and inspect Powertrain Control Module (PCM) connector for damaged, pushed-out or miswired terminals. If connector is not okay, repair as necessary. Perform TEST VER-2.
  12. If connector is okay, use an external ohmmeter to check resistance of CMP sensor signal circuit (Tan/Yellow wire) between PCM connector terminal No. 44 and CMP sensor connector. If resistance is more than 5 ohms, repair open in Tan/Yellow wire. Perform TEST VER-2.
  13. If resistance is less than 5 ohms, put scan tool in ohmmeter mode. Using scan tool, check resistance of PCM connector terminal No. 44, CMP sensor signal circuit (Tan/Yellow wire). If resistance is more than 5 ohms, replace PCM. Perform TEST VER-2. If resistance is less than 5 ohms, repair short to ground in Tan/Yellow wire. Perform TEST VER-2.
  14. Turn ignition off. Disconnect Camshaft Position (CMP) sensor connector. turn ignition on. Using scan tool in voltmeter mode, check voltage on Camshaft Position (CMP) sensor connector, 8-volt supply circuit (Orange wire). If voltage is less than 7 volts, repair open Orange wire. Perform TEST VER-2.
  15. If voltage is more than 7 volts, turn ignition off. Connect a jumper wire between signal circuit (Tan/Yellow wire) and ground circuit (Black/Light Blue wire) on CMP sensor connector harness side. Using scan tool, read Distributorless Ignition System (DIS) signal status. Make and break connection at CMP sensor connector several times while observing scan tool.
  16. If scan tool does not display CAM ONLY, go to next step. If scan tool displays CAM ONLY, turn ignition off. Remove CMP sensor. Inspect cam sprocket. If cam sprocket is okay, replace CMP sensor. Perform TEST VER-2. If cam sprocket is damaged, repair as necessary. Perform TEST VER-2.
  17. Turn ignition off. Put scan tool in ohmmeter mode. Check resistance of CMP sensor connector, ground circuit (Black/Light Blue wire). If resistance is more than 5 ohms, repair open in Black/Light Blue wire. Perform TEST VER-2.
  18. If resistance is less than 5 ohms, disconnect PCM connector. Inspect PCM sensor connector for damaged or pushed-out terminals. Repair as necessary. Perform TEST VER-2. If PCM connector terminals are okay, go to next step.
  19. Using an external ohmmeter, check resistance of signal circuit (Tan/Yellow wire) between CMP sensor connector harness side and PCM connector terminal No. 44. If resistance is more than 5 ohms, repair open in Tan/Yellow wire. Perform TEST VER-2.
  20. If resistance is less than 5 ohms, put scan tool in ohmmeter mode. Using scan tool, check resistance of CMP sensor connector, signal circuit (Tan/Yellow wire). If resistance is more than 5 ohms, replace PCM. Perform TEST VER-2. If resistance is less than 5 ohms, repair short to ground in Tan/Yellow wire. Perform TEST VER-2.
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