Aspen 4WD V8-5.7L Hybrid (2009)
Vacuum Pump: Testing and Inspection
VACUUM PUMP FUNCTIONAL TEST
Check for DTCs prior to performing this test because this test may cause DTCs to set in the Antilock Brake Module (ABS). Any fault in the
voltage/ground circuits of the Electric Vacuum Pump (EVP) will cause vacuum sensor DTCs to set in the ABS, therefore this test only checks the
vacuum output of a functioning EVP.
1. Disconnect the vacuum hose from the T-fitting on the booster side of T-fitting (side without check valve).
2. Connect a hand operated vacuum pump to the T-fitting.
3. With ignition key off, and door open, press on the brake pedal. The EVP should come on for approximately 5-10 seconds. If not, EVP or circuits
may be faulty, refer to DTC diagnostics. The pump should increase vacuum gauge reading to above 22 inches HG (745 millibars) of vacuum. If
not, and no leaks are present AND there are no DTCs, replace the EVP See: Service and Repair/Removal.
