Circuit/System Verification

Ignition - On / Vehicle - In Service Mode
Verify DTC P0556, P0557, P0558 is not set.
- If the DTC is set
  Refer to: DTC P0556, P0557, or P0558
- Go to next step: If the DTC is not set
Verify that the brake booster vacuum system has no damage, leakage or incorrect installation, refer to Brake Assist System Diagnosis
- If damage, leakage or incorrect installation is found
  Repair as necessary.
- Go to next step: If no damage, leakage or incorrect installation is found
Test or replace the component: B19B Brake Booster Vacuum Sensor
Ignition - On / Vehicle - In Service Mode
Verify the DTC does not set.
- If the DTC sets
  Replace the component: Power Brake Booster
- Go to next step: If the DTC does not set
All OK.