Throttle Position Sensor (TPS)

1991 Cadillac Seville STSSECTION Throttle Position Sensor (TPS)

Install jumper wires to enable connection of a DVOM in parallel between TPS harness connectors. Connect DVOM positive lead to Dark Blue TPS signal wire terminal. Connect negative lead to Black sensor ground wire terminal. See Fig 1 . Turn ignition on, engine off. Signal voltage should gradually change from less than one volt at closed throttle to about 5.0 volts at wide open throttle position. If reading is not as specified, adjust or replace TPS. See the appropriate article below:

  • D - ADJUSTMENTS - 4-CYL
  • D - ADJUSTMENTS - V6
  • D - ADJUSTMENTS - V8

A malfunction in the TPS circuit should set a related trouble code. For further TPS diagnostic information, refer to the appropriate G - TESTS W/ CODES article.

Fig 1: Throttle Position Sensor Circuit (Typical)
G91C07385Courtesy of GENERAL MOTORS CORP.
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:

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