Reductant Temperature Sensor 2 Circuit Range/Performance Problem
Issues with the second reductant temperature sensor reading.
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What it means (plain English)
The second temperature sensor for the diesel exhaust fluid (DEF) isn't reading properly, meaning the computer can't tell if the DEF is at the right temperature for effective operation.
What the computer is actually seeing
The engine control module (ECM) expects the temperature readings from the reductant temperature sensor 2 to fall within a normal range, typically between 0°C to 60°C (32°F to 140°F).
What a healthy reading looks like
Normal operation should have readings between 0°C and 60°C (32°F and 140°F) under standard conditions.
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.
- 11. Check the wiring and connectors to the reductant temperature sensor 2 for damage or corrosion. If any issues are found, repair or replace as necessary. Decision point: Are the connectors and wiring good?
- 22. Measure the resistance of the reductant temperature sensor 2 at ambient temperature. Compare the readings to the sensor specifications. If the resistance is out of range, replace the sensor. Decision point: Is the sensor faulty?
- 33. Use a scan tool to monitor the sensor data. Start the engine and let it reach operating temperature. Ensure the DEF temperature readings rise appropriately. Decision point: Are the readings normal under various engine conditions?
- 44. If the sensor and wiring are good but the code persists, consider reprogramming or updating the ECM. Decision point: Has reprogramming resolved the issue?
Common causes
- Faulty reductant temperature sensor
- Wiring or connector issues in the sensor circuit
- Coolant leaks affecting DEF temperature
- Software glitches in the ECM
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; fix it soon, as it can affect emissions compliance.
Will this code come back after clearing?
If the underlying issue isn't fixed, yes, it will likely return.
Why does this code pair with P2040?
They both relate to DEF temperature monitoring and can indicate problems with either sensor or the system.
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