Code 25, Intake Air Temperature High: Notes

1995 GMC Suburban K2500, 6.5 FSECTION Notes
WARNING: This page is about a different car, the 1995 GMC Sonoma and 1995 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Control module applies and monitors a voltage signal (4-6 volts) to intake air temperature sensor. When manifold air is cold, sensor resistance is high and control module sees a high signal voltage. As air warms, resistance decreases and voltage sensed by control module drops. Sensor resistance can be measured at sensor terminals with harness disconnected.

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. This checks if code is a hard failure or an intermittent condition.
  2. This simulates conditions for a Code 23. If scan tester displays a low temperature, control module and wiring are not at fault.
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:

  • 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.