BAS Solenoid Valve Circuit

BAS SOLENOID VALVE CIRCUIT





When Monitored and Set Condition
^ When Monitored: With the ignition on.
^ Set Condition: The Controller Antilock Brake (CAB) detects a Brake Assist System (BAS) Solenoid Valve malfunction.





For a complete Brake Assist System (BAS) Circuit Diagram refer to Diagrams; Electrical
Diagnostic Test
1. MEASURE THE RESISTANCE OF THE BAS SOLENOID VALVE 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the CAB harness connector.
Disconnect the BAS Brake Booster harness connector.

Note: Check connectors - Clean/repair as necessary.





Measure the resistance of the BAS Solenoid Valve 5-Volt Supply circuit from the CAB harness connector to the BAS Brake Booster harness connector.
Is the resistance below 5.0 ohms?
Yes >> Go to 2
No >> Repair the BAS Solenoid Valve 5-Volt Supply circuit for an open. Perform ABS VERIFICATION TEST. ABS Verification Test

2. MEASURE THE RESISTANCE OF THE BAS SOLENOID VALVE CONTROL CIRCUIT
With the ignition off.





Measure the resistance of the BAS Solenoid Valve Control circuit from the CAB harness connector to the BAS Brake Booster harness connector.
Is the resistance below 5.0 ohms?
Yes >> Go to 3
No >> Repair the BAS Solenoid Valve Control circuit for an open. Perform ABS VERIFICATION TEST.

3. MEASURE THE RESISTANCE OF THE BAS SOLENOID VALVE CIRCUITS
With the ignition off.





Measure the resistance between the BAS Solenoid Valve circuits at the BAS Brake Booster harness connector.
Is the resistance below 10K ohms?
Yes >> Repair the BAS Solenoid Valve circuits for a short to each other. Perform ABS VERIFICATION TEST.
No >> Go to 4

4. MEASURE THE VOLTAGE OF THE BAS SOLENOID VALVE 5-VOLT SUPPLY CIRCUIT
Turn the ignition on.





Measure the voltage of the BAS Solenoid Valve 5-Volt Supply circuit at the BAS Brake Booster harness connector.
Is voltage present?
Yes >> Repair the BAS Solenoid Valve 5-Volt Supply circuit for a short to voltage. Perform ABS VERIFICATION TEST.
No >> Go to 5

5. MEASURE THE VOLTAGE OF THE BAS SOLENOID VALVE CONTROL CIRCUIT
With the ignition on.





Measure the voltage of the BAS Solenoid Valve Control circuit at the BAS Brake Booster harness connector.
Is voltage present?
Yes >> Repair the BAS Solenoid Valve Control circuit for a short to voltage. Perform ABS VERIFICATION TEST.
No >> Go to 6

6. MEASURE THE RESISTANCE OF THE BAS SOLENOID VALVE 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.





Measure the resistance between ground and the BAS Solenoid Valve 5-Volt Supply circuit.
Is the resistance below 10K ohms?
Yes >> Repair the BAS Solenoid Valve 5-Volt Supply circuit for a short to ground. Perform ABS VERIFICATION TEST.
No >> Go to 7

7. MEASURE THE RESISTANCE OF THE BAS SOLENOID VALVE CONTROL CIRCUIT
With the ignition off.





Measure the resistance between ground and the BAS Solenoid Valve Control circuit.
Is the resistance below 10K ohms?
Yes >> Repair the BAS Solenoid Valve Control circuit for a short to ground. Perform ABS VERIFICATION TEST.
No >> Replace the BAS Brake Booster. Perform ABS VERIFICATION TEST.