Fuel Temperature Sensor A Circuit Low
The fuel temperature sensor circuit is reading lower than expected.
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What it means (plain English)
The fuel temperature sensor is telling the engine computer that the fuel is colder than it should be, which can cause performance issues and poor fuel efficiency.
What the computer is actually seeing
The engine control module (ECM) expects a fuel temperature around 140°F to 200°F (60°C to 93°C) under operating conditions. A reading lower than 32°F (0°C) for too long triggers this code.
What a healthy reading looks like
Fuel temperature should register between 140°F to 200°F (60°C to 93°C) when engine is running, below 32°F (0°C) is a fault.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check fuel temperature sensor wiring for damage or corrosion. Repair if necessary.
- 2Inspect connectors for cleanliness and secure fit. Clean or replace if needed.
- 3Use a scan tool to monitor the fuel temperature reading. If it remains below 32°F (0°C) with engine running, proceed to the next step.
- 4Test the fuel temperature sensor using a multimeter. Compare the resistance readings to the specifications provided by the manufacturer. If out of range, replace the sensor.
- 5If the sensor tests good, check the ECM for codes related to sending or receiving fuel temperature signals. If additional fault codes appear, address those first before replacing components.
Common causes
- Faulty fuel temperature sensor
- Wiring issues in the sensor circuit
- Connector corrosion or damage
- Cold ambient temperatures affecting sensor readings
- Faulty ECM affecting interpretation of sensor data
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s better to fix the issue soon to avoid performance loss and ensure engine efficiency.
Will this code come back after clearing?
If the underlying issue is not resolved, the code may come back after clearing the memory.
Why does this code pair with others like SPN 731?
They both relate to fuel system parameters; issues with one can affect readings and cause other faults to trigger.
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