Circuit/System Verification

Verify that the brake booster vacuum system has no damage, leakage or incorrect installation.
- If damage, leakage or incorrect installation is found
  Refer to Brake Assist System Diagnosis
- Go to next step: If no damage, leakage or incorrect installation is found
Ignition ON.
Verify the brake booster pump motor turns ON and OFF when commanding the Brake Booster Electric Vacuum Pump On and Off with a scan tool.
- If the brake booster pump motor does not turn ON and OFF
  Refer to Circuit/System Testing.
- Go to next step: If the brake booster pump motor turns ON and OFF
Verify the brake booster pump parameter is more than 40 kPa (12 in Hg) when commanding the brake booster electric vacuum pump ON.
- If the brake booster pump parameter is less than 40 kPa (12 in Hg)
  Replace the M9 Brake Booster Pump Motor.
- Go to next step: If the brake booster pump parameter is more than 40 kPa (12 in Hg)
All OK.