Engine Exhaust Temperature Sensor 1 Out of Range
The engine exhaust temperature sensor 1 reading is outside normal limits.
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What it means (plain English)
The exhaust temperature sensor is measuring temperatures that are too high or too low for the engine's operating conditions, which could indicate a sensor failure or exhaust system issue.
What the computer is actually seeing
The engine computer monitors the exhaust temperature sensor's signal voltage. It expects a range of 0.5V to 1.5V, corresponding to normal exhaust temperatures from 300°F to 900°F. If the voltage goes outside this range, the fault triggers.
What a healthy reading looks like
Expected voltage range from exhaust temperature sensor is 0.5V to 1.5V, correlating to temperatures of 300°F to 900°F.
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 connector at the exhaust temperature sensor for damage or corrosion. Repair if necessary. Decision point: If wiring is good, proceed to step 2; if damaged, fix it and recheck the code.
- 22. Measure the voltage output from the exhaust temperature sensor with a multimeter while the engine is running. Expect 0.5V to 1.5V. Decision point: If within range, proceed to step 3; if out of range, replace the sensor.
- 33. Check for exhaust leaks by inspecting the exhaust system visually and listening for leaks while the engine runs. Decision point: If leaks are found, repair them and recheck the code; if none found, suspect a faulty ECM.
Common causes
- Faulty engine exhaust temperature sensor
- Wiring or connector issue
- Exhaust leak causing false readings
- Exhaust gas contamination
- Faulty ECM/PCM
Typical repair cost
$$ - $$$
Related codes
Frequently asked questions
Can I still drive with this code?
Yes, but it's recommended to address it soon to avoid possible damage to the exhaust system or engine.
Will this code come back?
If the underlying issue isn't fixed, yes, the code will likely return.
Why does this code appear alongside SPN 3351?
SPN 3351 relates to a different temperature sensor in the exhaust system. Both sensors monitor exhaust temperatures for different functions.
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