1991 Geo Storm Base, 2D Hatchback, StandardFACTORY OEM SERVICE PROCEDURE

Code 32, EGR System Error (CALIF. Only)

A driver inside the ECM provides ground for EGR Vacuum Switching Valve (VSV). By turning the VSV on and off, ECM controls vacuum source to EGR modulator. EGR modulator regulates vacuum to EGR valve using exhaust back pressure.

The EGR gas temperature sensor, mounted in base of EGR valve, is used by the ECM to ensure EGR functions properly. The EGR gas temperature sensor contains a thermistor. ECM provides a 5-volt reference signal and a ground circuit for the EGR gas temperature sensor. ECM monitors EGR gas temperature sensor to determine if EGR valve functions when EGR is commanded upon. If EGR valve fails to open, EGR gas temperature sensor will signal low temperature to ECM. If EGR valve is stuck open, the EGR gas temperature sensor will indicate high temperature. Code 32 will be stored and the CHECK ENGINE light will illuminate.

Code 32 will set when one of the following conditions is present for 120 seconds:

  • High EGR temperature indicated at idle.
  • Low EGR temperature indicated when EGR is commanded upon.
  • Open or short in EGR gas temperature sensor circuit.

EGR is not enabled if coolant temperature is less than 69Β°F (21Β°C).

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. Checks for EGR gas temperature sensor 5-volt reference signal.
  2. Checks for a poor ground or an open ground wire.
  3. Checks for a short to voltage in EGR gas temperature sensor 5-volt reference signal.
  4. Checks EGR gas temperature sensor resistance.
  5. A non-functioning EGR valve will cause Code 32 to set.
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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.