Exhaust Temperature Sensor Circuit Range/Performance Problem
The exhaust temperature sensor has a problem with its range or performance.
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What it means (plain English)
The exhaust temperature sensor is supposed to send a specific voltage signal based on the temperature of the exhaust. If the temperature is too high or too low for the expected sensor output, the computer triggers this code to alert you.
What the computer is actually seeing
The ECM monitors the voltage from the exhaust temperature sensor. If it reads outside the expected range (e.g., below 0.2V or above 4.8V), it notes a performance issue.
What a healthy reading looks like
Expected voltage from the sensor should be between 0.2V and 4.8V depending on the exhaust temperature. A properly functioning sensor should fluctuate within this range as engine temperature changes.
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. Inspect the wiring and connectors at the exhaust temperature sensor for any signs of damage or corrosion. Fix any issues found. Decision Point: Are the connections good? (Yes: Go to step 2, No: Repair as needed)
- 22. Check the exhaust temperature sensor resistance with a multimeter. Use the manufacturer specifications for correct resistance values. Decision Point: Is the resistance within limits? (Yes: Go to step 3, No: Replace the sensor)
- 33. Test the voltage output of the exhaust temperature sensor while the engine operates at normal temperature. Decision Point: Is voltage between 0.2V and 4.8V? (Yes: Go to step 4, No: Replace the sensor)
- 44. Check for exhaust system backpressure with a gauge. Decision Point: Is backpressure within the manufacturer's specs? (Yes: Go to step 5, No: Address backpressure issue)
- 55. Clear the code and take the vehicle for a test drive. Check if the code returns. Decision Point: Did the code come back? (Yes: Replace ECM, No: Repair successful)
Common causes
- Faulty exhaust temperature sensor
- Wiring issues or damaged connectors
- Improper exhaust system backpressure
- Excessive carbon buildup on the sensor
- ECM software issue
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally drivable, but you should see this repaired soon to avoid potential damage to exhaust components.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code is likely to return.
Why does this problem sometimes pair with performance issues?
Incorrect exhaust temperature readings can impact fuel efficiency and emissions controls, which may lead to performance loss.
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