Diagnostic Hints

1992 Chevrolet Chevy Van G20, 5.0 HSECTION Diagnostic Hints
  1. If wire "A" (circuit 420) shorts to ground, check for blown fuse in 12-volt feed circuit. See TCC BATTERY FEED CIRCUITΒ  .
    NOTE: TCC BATTERY FEED CIRCUITΒ  does not include all possible fuses. Check vehicle wiring diagram.
    TCC BATTERY FEED CIRCUIT

    Vehicle Type & Body Code Check For Blown Fuse (Circuit 420)
    Passenger Cars
    B Gauges
    D G.A. Trans
    F Gauges
    Y Gauges
    Light Trucks & Vans
    C/K ECM/Ignition
    M Gauges
    R/V Gauges/Idle
    G Gauges
    S/T Ignition/Gauges
  2. If wire "D" (circuit 422) shorts to ground, 3 different conditions may occur:
    • TCC may engage if transmission is too hot and there is short in White wire between TCC and TCC switch.
    • Engine may idle rough. If transmission has 4th gear switch and there is short between ECM and switch, ECM always receives signal that transmission is in 4th gear. This may affect engine performance if spark timing depends on gear position.
  3. If wire "B" (circuit 446) shorts to ground, TCC will engage after a 1-2 shift (all except S and T truck with 2.5L engine).
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.