Engine Exhaust Temperature Sensor 1 - Data Valid but Above Normal Operating Range
Exhaust temperature too high from sensor 1.
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What it means (plain English)
The exhaust temperature sensor is telling the computer that the exhaust gases are getting hotter than they should be, which can happen if the engine runs too lean or if there's a problem with the exhaust system.
What the computer is actually seeing
The engine control module (ECM) reads the temperature from the sensor, which should normally be between 300°F to 1200°F (150°C to 650°C) during operation. If the reading exceeds the upper limit, this code is set.
What a healthy reading looks like
Normal operation range is between 300°F (150°C) and 1200°F (650°C).
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 exhaust temperature sensor wiring and connector for damage or corrosion. If found, repair or replace as needed. Check for continuity and shorts. If no issues, proceed to step 2.
- 22. Check the exhaust temperature sensor output voltage with a multimeter. At normal operating temperature, it should be within the expected range. If the readings are above 1200°F (650°C), replace the sensor. If normal, proceed to step 3.
- 33. Inspect the exhaust system for any leaks or restrictions that may cause high temperatures. If any leaks or blockages are found, repair them.
- 44. Analyze engine performance data using a scan tool. Check for fuel trim levels. If there's evidence of the engine running too lean (fuel trim values greater than +10%), further diagnostics on the fuel system may be required.
Common causes
- Faulty exhaust temperature sensor
- Wiring issues (shorts or opens)
- Exhaust leaks
- Engine running too lean
- Aftertreatment system malfunction
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's safer to fix this issue soon. If the exhaust temperature gets too high, it can cause damage to the turbo or the aftertreatment system.
Will this code come back after repairs?
If the underlying issue is fixed, such as a faulty sensor or exhaust leak, this code should not return.
Why does this code appear with loss of power or reduced performance?
High exhaust temperatures can indicate the engine is running inefficiently, which can result in power loss to protect engine components.
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