Aftertreatment Fuel Rate Control - Data Valid But Above Normal Operational Range
The fuel rate for aftertreatment is too high according to the engine control module.
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 is injecting more fuel into the exhaust system than it should, which can lead to excess emissions and poor engine performance.
What the computer is actually seeing
The engine control module (ECM) monitors the fuel delivery to the aftertreatment system. It expects a specific fuel rate, typically around 0.1 to 0.5 liters per hour during regeneration processes. When the rate exceeds preset thresholds (like 1.0 liters per hour), it triggers the SPN 0765 code.
What a healthy reading looks like
Normal fuel delivery rate for aftertreatment is around 0.1 to 0.5 L/hr during regeneration; anything above 1.0 L/hr is concerning.
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 for visible damage to wiring and connectors associated with the aftertreatment fuel injector. Repair any damaged wiring if found.
- 22. Verify fuel level in the tank. Make sure it’s adequate and appropriate for the vehicle’s operation. Fill if low.
- 33. Use a scan tool to check for any other active fault codes that may provide additional context; resolve any related issues first.
- 44. Measure the actual fuel delivery rate using a scan tool or diagnostic gauges. If it's over 1.0 L/hr, proceed to the next step.
- 55. Inspect and test the aftertreatment fuel injector for proper operation; testing should include checking resistance and functionality. If faulty, replace it.
- 66. If injector tests fine, check the fuel pressure; it should be within manufacturer specifications. If not, diagnose fuel supply issues or pressure regulation.
Common causes
- Faulty fuel injector
- Incorrect fuel pressure
- Faulty aftertreatment control module (ACM)
- Wiring issues to the fuel injector or ECM
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally drivable, but long-term operation with excessive fuel rates can lead to increased emissions and potential damage to the aftertreatment system.
Will this code come back after I clear it?
If the underlying issue isn't fixed, the code will likely return.
Why does this code appear with SPN 0766?
SPN 0765 and SPN 0766 are related as they both deal with the aftertreatment fuel control and could indicate similar issues.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →