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 insulation. Check 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 location of malfunction.
- Shifted Sensor: See TEMPERATURE-TO-RESISTANCE VALUES table to test ECT sensor at various temperature levels to evaluate possibility of a shifted (mis-scaled) sensor which may result in driveability complaints.
TEMPERATURE-TO-RESISTANCE VALUES (1)
| Temperature °F (°C) | Ohms | ||
|---|---|---|---|
| 212 (100) | 177 | ||
| 194 (90) | 241 | ||
| 158 (70) | 467 | ||
| 104 (40) | 1459 | ||
| 68 (20) | 3520 | ||
| 23 (-5) | 12,300 | ||
| 14 (-10) | 16,180 | ||
| 0 (-18) | 25,000 | ||
| -4 (-20) | 28,680 | ||
| -22 (-30) | 52,700 | ||
| -40 (-40) | 100,700 | ||
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