DTC 42, Fuel Temp Circuit Low (High Temp Indicated): Notes

Fuel temperature sensor is a thermistor that controls signal voltage to PCM. When fuel is cold, sensor resistance is high, and PCM will sense a high signal voltage. As fuel warms, sensor resistance becomes less and voltage drops. Fuel temperature sensor is integrated with optical sensor. DTC 42 will set when fuel temperature is greater than 215°F (102°C) for 2 seconds. PCM will default to poor idle quality during hot conditions.

1. This step determines if DTC 42 is result of a hard failure or an intermittent condition.
2. This step determines if fuel temperature signal circuit is shorted to ground.