Cause
Faulty exhaust aftertreatment fuel injector
The injector that sprays fuel into the exhaust stream to raise temperature for a particulate filter regeneration — a seventh injector on the exhaust side, not one of the cylinder injectors. Naming it precisely matters because the code reads like an engine fuelling fault and is not one, and a diagnosis that starts at the rail is starting in the wrong place.
Its position is what destroys it. It sits in the exhaust with combustion products flowing past its tip, so it cokes. A coked injector delivers a distorted or restricted spray, so regeneration temperatures are not reached, and the module reports its performance rather than its condition. A leaking one is worse — fuel entering the exhaust when none was commanded raises temperatures unpredictably and can be enough to damage the filter it exists to protect.
Distinguish the circuit codes from the performance codes before acting. Open, low and high name the wiring and the driver, and are answered with a meter. Performance and stuck-open codes name the injector body. Check for coking at the tip before fitting a new part, and be aware that a new injector into an exhaust system that coked the last one will coke as well unless what caused the excess soot is found.
Typically a moderate job.
Some of these codes mean you should stop driving
2 of the 5 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (5)
Codes where this is a likely explanation first, rather than merely a possible one.
- P20CF Exhaust Aftertreatment Fuel Injector A Stuck Open Likely for this code Stop driving Critical
- P20DB Exhaust Aftertreatment Fuel Supply Control Stuck Open Likely for this code Stop driving Critical
- P2697 Exhaust Aftertreatment Fuel Injector A Circuit/Open Likely for this code Moderate
- P2698 Exhaust Aftertreatment Fuel Injector A Performance Likely for this code High
- P2699 Exhaust Aftertreatment Fuel Injector A Circuit Low Moderate
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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