Engine Exhaust Temperature Sensor 1 - Circuit High
This code indicates a high voltage reading from the engine exhaust temperature sensor 1.
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 engine exhaust temperature sensor 1 measures the heat of the exhaust gases. If it shows a voltage that's too high (usually over 4.5 volts), it means the sensor or its wiring could be faulty.
What the computer is actually seeing
The engine control module (ECM) looks for the exhaust temperature sensor 1 voltage to be between 0.5V and 4.5V. If it exceeds 4.5V, the code is triggered.
What a healthy reading looks like
0.5V to 4.5V is normal; above 4.5V indicates a fault.
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 to the exhaust temperature sensor 1 for any visible damage, corrosion, or looseness. Decision Point: If damage is found, repair or replace before further testing.
- 22. Disconnect the exhaust temperature sensor 1 connector and perform a resistance check on the sensor. Expected resistance should be within 5 to 50 ohms. Decision Point: If resistance is out of range, replace the sensor.
- 33. With the key on, engine off, reconnect the sensor and measure voltage at the sensor connector. You should see a voltage between 0.5V and 4.5V. Decision Point: If voltage exceeds 4.5V, look for a short circuit or replace the sensor.
Common causes
- Faulty exhaust temperature sensor 1
- Short circuit in sensor wiring
- Corroded or loose connector
- Open circuit in sensor wiring
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's best to address this code promptly as it can affect engine performance and emissions.
Will the code come back after I reset it?
If the root cause isn't fixed, the code is likely to return.
Why does this code often pair with SPN 6411?
SPN 6411 indicates a low voltage issue, which can also stem from the same wiring or sensor problems.
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