What Does P1563 Mean?
This diesel fuel injection code indicates the fuel quantity control mechanism has reached its minimum adjustment limit. The system cannot reduce fuel delivery any further to meet targets.
Common Causes
35%
Fuel injector(s) leaking or over-delivering fuel
25%
Failed fuel pressure regulator causing excessive rail pressure
20%
High-pressure fuel pump delivering excessive fuel volume
15%
Faulty fuel rail pressure sensor providing incorrect feedback
5%
Contaminated or incorrect fuel affecting combustion
Diagnostic Steps
1
Step 1: Monitor fuel rail pressure at idle and under load; compare to specifications
2
Step 2: Perform cylinder contribution test to identify leaking or over-fueling injectors
3
Step 3: Check fuel pressure regulator operation and return fuel flow rate
4
Step 4: Verify fuel rail pressure sensor accuracy with mechanical gauge
5
Step 5: Inspect for fuel contamination and check injector leak-back rates
Estimated Repair Cost
$400 - $3,000
Parts + labor, varies by vehicle and location
This diesel fuel injection code indicates the fuel quantity control mechanism has reached its minimum adjustment limit. The system cannot reduce fuel delivery any further to meet targets.
The most common cause of P1563 (Quantity Adjuster Lower Limit Attained) is: Fuel injector(s) leaking or over-delivering fuel
Typical repair costs for P1563 range from $400 to $3,000, depending on the vehicle, location, and whether you do it yourself or go to a shop.
May cause rough running, excessive smoke, and poor performance. Generally safe to drive short distances but requires prompt attention.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1563 to identify the root cause.
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Quick Info
Category
Powertrain
System
Diesel Fuel Injection System
Difficulty
Type
Manufacturer
Recommended Tools
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