Diagnostic Aids
Tech 1 displays engine temperature in degrees Celsius (°C) and Fahrenheit (°F). After engine is started, temperature should rise steadily to 194°F (90°C), then stabilize when thermostat opens. An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check the following for:
- A short to ground in circuit No. 410 (Yellow wire).
- Intermittent Test: Using Tech 1, monitor engine coolant temperature while moving related connectors and wiring harness. If failure is induced, display will change. This may assist in isolating the location of the malfunction.
- Shifted Sensor: See TEMPERATURE-TO-RESISTANCE VALUES to test ECT sensor at various temperature levels to evaluate the possibility of a shifted (mis-scaled) sensor which may result in driveability complaints.