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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-37A - Injector Control Circuits (DTC 27)

Test TC-37A - Injector Control Circuits (DTC 27)

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 engine will not start, crank engine for at least 10 seconds.
  2. Using scan tool, read DTCs. If engine starts, allow engine to idle for at least 20 seconds. If scan tool does not display INJECTOR CONTROL CIRCUIT, condition required to set DTC is not present at this time. Go to next step. If scan tool displays INJECTOR CONTROL CIRCUIT, go to appropriate test. See INJECTOR DTCS table below.
    INJECTOR DTCS

    DTC Go To
    INJECTOR #1 CONTROL CIRCUIT TC-37B 
    INJECTOR #2 CONTROL CIRCUIT TC-38A 
    INJECTOR #3 CONTROL CIRCUIT TC-39A 
    INJECTOR #4 CONTROL CIRCUIT TC-40A 
    INJECTOR #5 CONTROL CIRCUIT TC-41A 
    INJECTOR #6 CONTROL CIRCUIT TC-42A 
    INJECTOR #7 CONTROL CIRCUIT TC-43A 
    INJECTOR #8 CONTROL CIRCUIT TC-44A 
  3. INJECTOR CONTROL CIRCUIT DTC sets if Powertrain Control Module (PCM) does not detect injector "turn-off edge" when expected. Possible causes are: open or shorted injector control circuit, open injector power supply circuit, open injector, or failed driver in 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 injectors 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 DTC CONDITION  . Perform TEST VER-2.