Exhaust Gas Temperature Sensor 1 - Circuit High
The exhaust gas temperature sensor 1 circuit is reporting a high voltage.
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What it means (plain English)
The sensor that measures how hot the exhaust gases are is sending a signal that is too high, usually over 5 volts, making the engine control unit think something's wrong.
What the computer is actually seeing
The engine control unit sees a voltage reading from the exhaust gas temperature sensor that is higher than the expected range, indicating a possible sensor failure or wiring issue.
What a healthy reading looks like
Expected voltage from the exhaust gas temperature sensor should be between 0.5 to 4.5 volts during normal operation; over 5 volts is considered too high.
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 connectors for the exhaust gas temperature sensor for any damage, corrosion, or disconnections. 🔍
- 22. Using a multimeter, check the voltage at the exhaust gas temperature sensor connector with the engine running. Confirm voltage readings. ✅
- 33. If the voltage is above 5 volts, disconnect the sensor and recheck the voltage at the connector. If the voltage drops to normal, the sensor is faulty. If not, investigate the wiring harness. 🔄
- 44. If the voltage is normal with the sensor disconnected, replace the exhaust gas temperature sensor. 🔧
- 55. If the sensor is replaced and the problem persists, inspect the Engine Control Module (ECM) for issues. ⚙️
Common causes
- Faulty exhaust gas temperature sensor
- Shorted wiring harness
- Corroded connectors
- Loose connections
- ECM failure
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to fix this soon since it could affect emissions and engine performance.
Will this code come back after resetting?
If it’s a wiring issue or a bad sensor, yes, it will likely return.
Why does this code pair with other SPN codes?
Related codes usually indicate multiple issues with the exhaust system or related sensors.
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