Component Testing

Fuel Temperature Sensor 

Measure and record the resistance between the signal terminal 5 and the low reference circuit terminal 3 at the fuel temperature sensor. The sensor resistance at 20°C (68°F) should be 2300 - 2700 Ω, and at 50°C (122°F) should be 790 - 900 Ω.

• If the sensor resistance does not closely match through the temperature ranges, replace the B48 Fuel Temperature Sensor.

IAT Sensor 

Measure and record the resistance between the signal terminal F and the low reference circuit terminal E at the IAT sensor. Compare the value to the Temperature vs Resistance table. Refer to Temperature Versus Resistance - Intake Air Temperature Sensor .

• If the IAT sensor does not closely match the temperature ranges, replace the B75 MAF/IAT sensor.