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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 43 (Engine Controls - Tests W/Codes - 8.0L) >> Self-Diagnostic Tests >> Test TC-28A - Injector Control Circuits (DTC 27)

Test TC-28A - Injector Control Circuits (DTC 27)

WARNING: This page is about a different car, the 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 diagrams, 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 engine starts, allow engine to idle for at least one minute. If scan tool does not display INJECTOR CONTROL CIRCUIT, condition required to set trouble code is not present at this time. Go to next step. If scan tool displays INJECTOR CONTROL CIRCUIT, go to appropriate test. See INJECTOR TROUBLE CODES table.
    INJECTOR TROUBLE CODES

    Trouble Code Go To
    INJECTOR #1 CONTROL CIRCUIT TC-28B 
    INJECTOR #2 CONTROL CIRCUIT TC-29A 
    INJECTOR #3 CONTROL CIRCUIT TC-30A 
    INJECTOR #4 CONTROL CIRCUIT TC-31A 
    INJECTOR #5 CONTROL CIRCUIT TC-32A 
  3. INJECTOR CONTROL CIRCUIT trouble code sets if Powertrain Control Module (PCM) does not detect an inductive kick when expected. Possible causes are: open or shorted injector driver circuit, open Auto Shutdown (ASD) relay supply circuit, open injector, failed PCM, faulty wiring or faulty connectors. 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.