Vacuum Pump Control Circuit B / Open
The controller cannot drive the secondary electric vacuum pump (B). Brake servo or HVAC actuators that depend on engine vacuum may not get enough vacuum during low-load operation or with engine off in stop-start mode.
Affected components
- Vacuum pump b
- Pump relay
- Wiring harness
Common causes
- High likelihood: Open pump motor winding or worn brushes
- Medium likelihood: Broken control wire between ECU and pump
Diagnostic notes
- The malfunction indicator lamp may illuminate
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.