Diagnostic Aids

1993 Chevrolet Sportvan G20, 5.7 KSECTION Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Check PCM harness connector for backed out terminals. Connect a DVOM between affected terminal and ground. Wiggle related wires and connectors while watching DVOM for voltage reading change. Ensure coolant temperature sensor is not scaled improperly. See Code 15 in appropriate TESTS W/CODES article in this section. Ensure engine cooling system is operating normally.

Fig 1: Cooling Fan Circuit Diagram (3.8L)
G92B15918Courtesy of GENERAL MOTORS CORP.
RENDER: 1.0x

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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.