Exhaust Gas Temp Sensor 1 Circuit
This code indicates a problem with the exhaust gas temperature sensor 1 circuit.
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What it means (plain English)
The exhaust gas temperature sensor measures how hot the exhaust gases are after they leave the engine. If the sensor is faulty or its wiring is damaged, the engine computer can't get accurate readings, which can affect performance and emissions.
What the computer is actually seeing
The Engine Control Module (ECM) expects the exhaust gas temperature (EGT) signal to fluctuate between 0.5V to 4.5V based on the temperature of the exhaust gases. If the voltage stays too high, too low, or if there's an open circuit, the ECM sets this fault code.
What a healthy reading looks like
Expected voltage from the EGT sensor should range from 0.5V (cold) to 4.5V (hot).
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 visible damage or corrosion. Repair as necessary.
- 22. Using a multimeter, check the voltage output of the exhaust gas temperature sensor at operating temperature. Expected values should be between 0.5V and 4.5V. Note any abnormalities.
- 33. If voltage is out of range, disconnect the sensor and check resistance across the sensor terminals. Verify that it matches manufacturer specifications.
- 44. If the sensor resistance is okay and wiring seems intact, consider replacing the exhaust gas temperature sensor.
Common causes
- Faulty exhaust gas temperature sensor
- Damaged wiring or connector to the EGT sensor
- Corroded or loose electrical connections
- Exhaust system leaks affecting temperature readings
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It is not recommended to drive with this code as it can affect emissions and vehicle performance.
Will this code come back after clearing it?
If the underlying issue is not repaired, the code will likely return after clearing.
Why does this code pair with others?
This code often relates to other sensors or circuits in the exhaust system that can affect temperature readings.
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