Exhaust Gas Temperature Sensor 1
Indicates a problem with the exhaust gas temperature sensor on the engine.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The exhaust gas temperature sensor measures how hot the gases are coming out of the engine. If it fails, the engine computer can't tell if the exhaust is heating properly, which can lead to issues with engine performance and emissions.
What the computer is actually seeing
The engine control module (ECM) expects a signal from the exhaust gas temperature sensor. Typically, this should range from 0.5V to 4.5V depending on the temperature. If the signal is too low or too high, a fault is logged.
What a healthy reading looks like
Expected voltage from the sensor: 0.5V (200°F) to 4.5V (1400°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. Check the wiring and connectors to the exhaust gas temperature sensor for any visible damage or loose connections.
- 22. Inspect the exhaust system for leaks that might affect the sensor readings.
- 33. Use a multimeter to measure the voltage at the sensor connector. Confirm it falls within 0.5V to 4.5V when the engine is running. If not, replace the sensor.
- 44. If the sensor voltage is within range, check the ECM for proper programming and updates.
Common causes
- Faulty exhaust gas temperature sensor
- Wiring or connector issues
- Exhaust leaks affecting sensor performance
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's advisable to fix it soon, as it can affect emissions and engine performance.
Will this code come back after I clear it?
If the underlying issue isn't resolved, the code will likely return.
Why does this code pair with SPN 970?
SPN 970 tracks similar temperature readings from a different location in the exhaust system, helping diagnose systemic issues.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →