Engine Exhaust Temperature Sensor A Circuit High
The Engine Exhaust Temperature Sensor A is reporting high voltage.
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What it means (plain English)
The exhaust temperature sensor measures how hot the exhaust is. When it gets too much voltage (above 5 volts), it sends a signal that something’s wrong.
What the computer is actually seeing
The Engine Control Module (ECM) sees a voltage signal from the exhaust temperature sensor A that exceeds the maximum threshold, usually around 5 volts.
What a healthy reading looks like
A normal exhaust temperature sensor reading should be below 5 volts, typically between 0.5 to 4.5 volts depending on temperature.
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 for any visible damage or shorts to power, especially near the sensor itself.
- 22. Check the connector for corrosion or poor connection; clean or repair as necessary.
- 33. Use a multimeter to measure the voltage at the sensor connector with the ignition on (engine off). Expected voltage should be between 0.5V and 4.5V. If voltage is above 5V, proceed to the next step.
- 44. Disconnect the exhaust temperature sensor and recheck the voltage at the connector. If voltage returns to normal (below 5V), replace the sensor. If it's still high, inspect the wiring back to the ECM for shorts.
- 55. If the wiring is intact, check for grounding issues, ensuring the sensor shares sufficient ground with the ECM.
Common causes
- Wiring harness short to power (likely +12V)
- Faulty exhaust temperature sensor
- Ground issues affecting sensor operation
- Connector corrosion or damage
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but fix soon. High exhaust temps can damage components over time.
Will this code come back after I clear it?
If the underlying issue isn't fixed, the code is likely to return.
Why is this paired with other temperature codes?
Multiple temperature sensors might share wiring or be affected by the same failure, pulling additional codes.
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