Engine Exhaust Temperature Sensor 1 Above Threshold
This code indicates that the exhaust temperature is higher than the permissible limit.
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 management system is detecting that the exhaust temperature sensor 1 is reporting a temperature higher than expected, typically over 850°C (1562°F), which could point to issues such as a failing sensor, clogged DPF, or exhaust leaks.
What the computer is actually seeing
The powertrain control module (PCM) is receiving input from the exhaust temperature sensor. If the sensor reads a temperature above 850°C (1562°F) repeatedly, this fault code is triggered after a specified time.
What a healthy reading looks like
Exhaust gas temperature should normally stay below 850°C (1562°F). Check values during normal operation should be around 350°C (662°F) to 700°C (1292°F) under load.
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 the exhaust temperature sensor wiring for damage or corrosion.
- 2Test the resistance of the exhaust temperature sensor with a multimeter; it should have a range close to 750-1500 ohms at room temperature.
- 3Inspect for exhaust leaks or a clogged DPF; monitor exhaust gas flow and temperatures before and after the DPF.
- 4If the sensor tests good, check the vehicle’s live data for actual exhaust temperatures to confirm the reading is accurate.
- 5If the readings are within normal parameters, consider testing or reprogramming the PCM.
Common causes
- Faulty exhaust temperature sensor
- Open or shorted wiring in the sensor circuit
- Exhaust leaks affecting temperature readings
- Clogged diesel particulate filter (DPF)
- PCM calibration issue
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this fault code?
It's best to fix this issue soon to avoid engine damage, but you may be able to drive short distances if performance isn't affected.
Will this code come back after resetting?
If the underlying issue isn't fixed, the code will likely return after a drive cycle.
Why does this code appear if I’ve recently replaced my DPF?
Improper installation or a fault with the new DPF could still be causing high exhaust temperatures.
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