1993 Geo Tracker LSi, AutomaticFACTORY OEM SERVICE PROCEDURE

Diagnostic Aids

After engine is started, temperature should rise steadily to about 203Β°F (95Β°C) and then level off when thermostat opens.

Ensure engine is not overheating and has not been subjected to conditions which would create an overheating condition (i.e., overload, trailer towing, heavy stop and go traffic, etc.).

When replacing ECT sensor, check TEMPERATURE TO RESISTANCE VALUES table. A "shifted" sensor could result in poor driveability complaints.

Fig 1: Code 15 - Schematic Engine Coolant Temperature Sensor Circuit, High Temp. Indicated
G93J78955
Factory Service Tools

Use the Manual With the Right Hardware

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

Disclosure: Verified tool recommendations may earn an affiliate commission at no 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.