Diagnostic Aids

DTC indicates that ECT sensor readings are valid, but deviate more than 12°F (12°C) from ECM modeled temperature.

Possible causes:

• Skewed sensor.
• Very low or very high ambient temperatures.
• Corrosion in connector or resistance in wiring.
• Poor connections in ECT circuit.
• Thermostat malfunction.
• Cooling fan(s) malfunction.
• Extreme ambient temperature.

ECT sensor reading may be compared to IAT sensor reading on scan tool after vehicle has been sitting more than 6 hours with ignition off. Both readings should be within 10°F (6°C) of each other.

For resistance values, see TEMPERATURE VS RESISTANCE  table under DTC P0115: ECT SENSOR CIRCUIT.