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 the brake booster vacuum system has none of the conditions listed below:
- Vacuum leak
- Damaged, defective, or loose component:
- If a condition exists
  Refer to: Brake Assist System Diagnosis
- Go to next step: If no condition exists
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: K17 Electronic Brake Control Module
- Go to next step: If the DTC does not set
All OK.