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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 41 (Engine Controls - Tests W/Codes - 5.9L Gasoline) >> Self-Diagnostic Tests >> Test TC-3A - No Cam Sync Signal At Pcm

Test TC-3A - No Cam Sync Signal At Pcm

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION  . For wiring diagram, see WIRING DIAGRAMS  section at the end of this article.
  1. Using scan tool, erase trouble codes. Attempt to start engine. If engine will not start, crank engine for at least 10 seconds.
  2. Using scan tool, read trouble codes. If scan tool does not display NO CAM SYNC SIGNAL AT PCM, condition required to set trouble code is not present at this time. Go to next step. If scan tool displays NO CAM SYNC SIGNAL AT PCM, go to step 6).
  3. NO CAM SYNC SIGNAL AT PCM trouble code sets if Powertrain Control Module does not see Camshaft Position (CMP) sensor signal with Crankshaft Position (CKP) signal present. Possible causes are: failed CMP sensor, open or shorted CMP sensor signal circuit (Tan/Yellow wire), open CMP sensor 8-volt supply circuit (Orange wire), open CMP sensor ground circuit (Black/Light Blue wire), damaged pulse ring or failed PCM. Go to next step.
  4. Inspect all related wiring and connectors. Repair as necessary. Perform TEST VER-2. If no problems are found with wiring and connectors, go to next step.
  5. Start engine. Wiggle wiring harness from CMP sensor to PCM. If engine misfires or stalls, repair wiring harness as necessary. Perform TEST VER-2. If engine does not misfire or stall, see INACTIVE TROUBLE CODE CONDITION  . Perform TEST VER-2. If engine does not misfire or stall, test is complete.
  6. Turn ignition off. Disconnect Camshaft Position (CMP) sensor connector. Using scan tool in voltmeter mode, check voltage on CMP sensor connector, 8-volt supply circuit (Orange wire). If voltage is less than 7 volts, repair open Orange or White/Black wire. Perform TEST VER-2.
  7. If voltage is more than 7 volts, connect a jumper wire to CMP signal circuit (Tan/Yellow wire) on CMP sensor connector harness side. Using other end of jumper wire, make and break connection at CMP sensor ground circuit (Black/Light Blue wire) on sensor connector several times. Without turning ignition off, attempt to start engine. If engine starts, replace CMP sensor. Perform TEST VER-2. If engine does not start, go to next step.
  8. Turn ignition off. Remove distributor cap. While observing distributor rotor, have an assistant crank engine. If rotor does not turn as engine is cranked, repair distributor drive system as necessary. Perform TEST VER-2.
  9. If rotor turns, turn ignition off. Check resistance of CMP sensor connector ground circuit (Black/Light Blue wire) using scan tool in ohmmeter mode. If resistance is more than 5 ohms, repair open Black/Light Blue wire. Perform TEST VER-2.
  10. If resistance is less than 5 ohms, disconnect Powertrain Control Module (PCM) connector. Inspect PCM connector for damaged or pushed-out terminals. Repair as necessary. Perform TEST VER-2. If PCM connector terminals are okay, go to next step.
  11. Using an external ohmmeter, check resistance of CMP 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 Tan/Yellow wire or Gray/Black wire. Perform TEST VER-2.
  12. If resistance is less than 5 ohms, check resistance of PCM connector terminal No. 44 (Tan/Yellow wire) using scan tool in ohmmeter mode. 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 or Gray/Black wire. Perform TEST VER-2.
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