Engine Exhaust Temperature Sensor 1 High
The engine's exhaust temperature sensor is reporting a high value.
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What it means (plain English)
The exhaust temperature sensor measures how hot the exhaust gases are. If it's showing too high of a number, it usually means there's a problem with the sensor or the exhaust system.
What the computer is actually seeing
The engine control module (ECM) receives voltage readings from the exhaust temperature sensor. Normally, the voltage should be in the range of 0.5 to 4.5 volts corresponding to exhaust temperatures of 300°F to 1500°F (approx. 150°C to 815°C). If it reads above 4.5 volts, it triggers a fault code.
What a healthy reading looks like
Expect the exhaust temperature sensor output to be between 0.5V (low temp) and 4.5V (high temp). Anything above 4.5V indicates a fault condition.
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 connector for the exhaust temperature sensor. Look for frays or corrosion. If they’re damaged, repair or replace them.
- 22. Test the exhaust temperature sensor output using a multimeter. It should be between 0.5V and 4.5V at operating temperature.
- 33. If the sensor output is above 4.5V or no change is detected, replace the sensor and retest.
- 44. If the code returns after replacing the sensor, inspect the exhaust system for blockages or other components that could lead to excessively high temperatures.
Common causes
- Faulty exhaust temperature sensor
- Wiring issues or short circuits in the sensor circuit
- Exhaust system blockages causing abnormal temperature readings
- Excessive fuel burning in the engine, causing higher-than-normal exhaust temperatures
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity suggests it's best to fix soon to avoid damage but it may still be drivable for a short period.
Will the code come back after fixing?
If the sensor or wiring was the issue, fixing it should clear the code. If the exhaust system has underlying problems, it may return.
Why does this code appear with other SPN codes?
It’s common for exhaust-related issues to create multiple fault codes as different sensors monitor similar parameters.
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