REGENERATION INHIBIT - EXHAUST TEMPERATURE HIGH
The system has detected a high exhaust temperature that inhibits regeneration.
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)
When your engine runs a cleaning process for the emissions system, it heats the exhaust a lot. If it sees temps too high, it stops this process to protect parts.
What the computer is actually seeing
The engine control unit (ECU) monitors the exhaust temperature via a sensor and sees readings above a set threshold, typically around 950°F (510°C).
What a healthy reading looks like
Exhaust temperature should stay below 950°F (510°C) during normal operation.
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 connector at the exhaust temperature sensor. Look for any signs of damage or corrosion. If any issues, repair them first and retest.
- 22. With the ignition on, use a scanner to monitor the exhaust temperature sensor's data. It should read below 950°F (510°C) during normal operation. If it's way higher, replace the sensor.
- 33. Inspect the diesel exhaust fluid quality and level; a poor quality or low level can affect exhaust temperatures. Refill or replace as necessary and check again.
- 44. Check for any active DTCs related to the fuel/injector system. If there are DTCs pointing to fuel delivery issues, resolve those as they may affect combustion temperature.
Common causes
- Faulty exhaust temperature sensor
- Damaged wiring or connectors to the temperature sensor
- Excessive heat from a stuck open injector
- Partially clogged DPF causing higher temperatures
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's not recommended to drive as the high exhaust temperatures can damage components like the turbo or DPF.
Will this code come back after clearing?
If the underlying issue isn't fixed, the code will likely return after a few drive cycles.
Why might this code show up with other SPNs?
Codes related to emissions and exhaust temperature often trigger together due to interconnected systems, especially around the DPF and SCR processes.
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