Fuel Volume Regulator B Control Circuit Open
An open circuit is detected on the control line for the second fuel volume regulator (B) used on twin high-pressure-pump diesel systems. Without this regulator the high-pressure pump cannot meter fuel for its assigned cylinder bank, leading to rail-pressure faults and limp-home behaviour.
Affected components
- Fuel volume regulator b
- High pressure pump b
- Fuel rail
Common causes
- High likelihood: Open in harness or connector to regulator B
- Medium likelihood: Regulator solenoid winding open
- Low likelihood: Pin pushed back out of connector body
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.