Exhaust Temperature Sensor 1 - Voltage Above Normal
The exhaust temperature sensor reading is higher than the expected voltage range.
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What it means (plain English)
The exhaust temperature sensor checks how hot the exhaust gases are. If the sensor sends a voltage signal that’s too high, it means the sensor could be defective, or the exhaust is too hot, leading to potential issues with the engine or aftertreatment systems.
What the computer is actually seeing
The ECU sees a voltage signal from the exhaust temperature sensor that exceeds the normal operating range, typically above 4.5 volts.
What a healthy reading looks like
Normal voltage should range from 0.5V to 4.5V under operating conditions; anything above that indicates an issue.
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 for the exhaust temperature sensor for damage or corrosion. Repair as necessary.
- 22. Measure the voltage at the sensor connector. Expect 0.5V to 4.5V when the system is operating correctly. If voltage is over 4.5V, go to step 3.
- 33. Check the resistance of the sensor itself per manufacturer's specifications to confirm it's within range. Replace if out of specs.
- 44. If steps 1-3 are good, measure the exhaust temperature near the sensor directly using a non-contact thermometer to confirm actual temperatures. Compare with expected values based on engine load and operating conditions.
Common causes
- Faulty exhaust temperature sensor
- Short circuit in the sensor circuit
- Open circuit or poor connection
- Exhaust system overheating
- Wiring harness damage or corrosion
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's not recommended to drive for long; the exhaust could overheat and cause damage.
Will this problem come back after repair?
If the cause is properly fixed, it shouldn't return.
Why does this code pair with other temperature sensor codes?
These codes often indicate similar issues with the exhaust system, correlating to overheating or sensor failures.
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