FMI 7 - Exhaust Temperature Sensor Circuit High
The exhaust temperature sensor signal is reading higher than expected.
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What it means (plain English)
The exhaust temperature sensor is giving a high signal, which means it's detecting hotter exhaust than normal, possibly indicating an issue with the exhaust system or a faulty sensor.
What the computer is actually seeing
The engine control unit (ECU) is monitoring the exhaust temperature via the sensor input. It's receiving a voltage signal that corresponds to exhaust temperature but it's outside the normal range, often above 300 degrees Celsius.
What a healthy reading looks like
Normal exhaust temperature readings should typically be between 150°C to 500°C depending on engine load and conditions.
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.
- 1Check for any visual damage to the exhaust temperature sensor and its wiring.
- 2Using a multimeter, measure the voltage from the exhaust temperature sensor while the engine is running. Normal operation should give a reading within 0.5V to 4.5V depending on temperature conditions.
- 3If the reading is high (above 4.5V) or outside expected parameters, check the connector for corrosion or poor connections. Fix any found issues.
- 4If the sensor tests good, inspect the exhaust system for leaks or restrictions that could affect temperature readings. Pay attention to any repair history that may relate to these issues.
- 5If exhaust system checks out, replace the exhaust temperature sensor and erase the code before retesting the vehicle.
Common causes
- Faulty exhaust temperature sensor
- Wiring issues or short circuits in the sensor circuit
- Exhaust leaks or restrictions
- Failed engine components causing excessive heat
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's best to avoid driving until you address the issue, as it can lead to further problems such as emissions failure or damage to the engine.
Will this code come back after I fix it?
If the root cause is resolved, the code should not return; however, if there's an underlying issue not addressed, it may come back.
Why is this related to exhaust temperature?
The code specifically monitors the exhaust temperature sensor to ensure proper operation of emissions systems, preventing damage from excessive heat.
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