What Does P20DB Mean?
The PCM detects the aftertreatment fuel injector is stuck in the open position, allowing continuous uncontrolled fuel flow. This can damage exhaust components and create safety hazards.
Safety Warning
Critical condition - excess fuel in exhaust creates fire hazard and can cause thermal damage to DPF or catalyst. Vehicle should not be driven until repaired.
Common Causes
45%
Mechanically stuck or seized aftertreatment fuel injector
25%
Contaminated fuel causing injector sticking
20%
Failed injector return spring or internal component
8%
Shorted injector driver circuit keeping injector energized
2%
Debris or carbon buildup preventing injector closure
Diagnostic Steps
1
Step 1: Monitor fuel flow rate and injector commanded state using scan tool live data
2
Step 2: Check for excessive fuel consumption or visible fuel leaking from exhaust
3
Step 3: Disconnect injector and verify flow stops to confirm mechanical failure
4
Step 4: Inspect fuel quality and check for contamination in fuel system
5
Step 5: Remove injector and bench test for proper opening/closing operation
Estimated Repair Cost
$500 - $1,800
Parts + labor, varies by vehicle and location
The PCM detects the aftertreatment fuel injector is stuck in the open position, allowing continuous uncontrolled fuel flow. This can damage exhaust components and create safety hazards.
The most common cause of P20DB (Exhaust Aftertreatment Fuel Supply Control Stuck Open) is: Mechanically stuck or seized aftertreatment fuel injector
Typical repair costs for P20DB range from $500 to $1,800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Critical condition - excess fuel in exhaust creates fire hazard and can cause thermal damage to DPF or catalyst. Vehicle should not be driven until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P20DB to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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