Coolant Temperature Sensor (Cts)

1991 GMC S15 Jimmy 2D Utility, RWD, StandardSECTION Coolant Temperature Sensor (Cts)

If a coolant sensor-related code is present, see appropriate article below:

An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. Disconnect coolant temperature sensor connector. Measure resistance between sensor terminals. Resistance should be high when engine is cold and drop as engine warms up. See CTS RESISTANCE VALUES table.

CTS RESISTANCE VALUES

Temperature °F (°C) Resistance (Ohms)
210 (100) 185
160 (70) 450
100 (38) 1800
70 (20) 3400
20 (-7) 13,500
0 (-18) 25,000
-40 (-40) 100,700
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.