Code 23, Throttle Position Sensor MISADJUSTED: Notes

1992 GMC Value Van 4.3 Z, AutomaticSECTION Notes

The Throttle Position Sensor (TPS), a variable mechanical resistor, informs ECM of throttle opening. The TPS, connected to a 5-volt reference signal, has a high resistance value at closed throttle. At wide open throttle, TPS resistance is at its lowest, and output to ECM will be close to 5 volts. Code 23 indicates ECM has noted that voltage, at terminal A2, is not .25-1.35 volts for at least 30 seconds, with engine speed at 550-650 RPM.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. This confirms Code 23 fault is present.
  2. This test determines if sensor signal line is shorted to ground.
  3. See THROTTLE POSITION SENSOR in N - REMOVE/INSTALL/OHAUL article.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.