Diagnostic Aids

1987 Chevrolet Step Van P20, 7.4 W, Automatic, 400/M40SECTION Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 1994 GMC Vandura Special, 1994 GMC Vandura, 1994 GMC Suburban, 1994 GMC Rally Camper Special, and 1994 GMC Rally. However, it is still accessible from the selected car via links, so may be relevant.

Prior to replacing PCM, check resistance of all PCM-controlled solenoids and relays. Replace any with a resistance value less than 20 ohms. EVRV solenoid cannot be checked with a DVOM due to solid state circuitry.

Fig 1: Code 32 Schematic ("C" & "K" Series) EGR Circuit Error Models Using Ported Vacuum & EVR Solenoid
G94E65999
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.