Pinpoint Test J: Poor Vehicle Tracking During Anti-Lock Function
WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
- J1 BLEED THE BRAKE SYSTEM
- Bleed the brake system using the diagnostic tool. Refer to BRAKE SYSTEM-GENERAL INFORMATION .
- Test drive the vehicle.
- Does the vehicle still track poorly?
- Yes : GO to J2.
- No : The brake system is operating correctly. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .
- J2 CHECK THE ABS INLET VALVE (CLOSED POSITION)
- Key in OFF position.
- Connect the diagnostic tool.
- Key in ON position.
- Raise and support the vehicle. Refer to JACKING & LIFTING .
- Rotate all the wheels to make sure they rotate freely (the transaxle must be in NEUTRAL).
- Trigger the ABS module LF INLET ON active command.
- Apply moderate brake pedal effort.
- Have an assistant attempt to rotate the LF wheel.
- Does the LF wheel rotate?
- Yes : TRIGGER the LF INLET OFF active command. GO to J3.
- No : INSTALL a new HCU. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .
- J3 CHECK THE ABS INLET VALVE (OPEN POSITION)
- Apply moderate brake pedal effort.
- Have an assistant attempt to rotate the LF wheel.
- Does the LF wheel rotate?
- Yes : INSTALL a new HCU. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .
- No : GO to J4.
- J4 CHECK THE ABS OUTPUT VALVE (OPEN POSITION)
- Apply moderate brake pedal effort.
- Trigger ABS module LF INLET ON active command.
- Trigger ABS module ABS POWER ON active command (turns on pump motor) for 6 seconds. (Trigger must be pressed 3 times. Each press runs the pump for 2 seconds.)
- Trigger the ABS module LF OUTLET ON active command, then trigger the ABS module LF OUTLET OFF active command. Repeat 3 times.
- Have an assistant attempt to rotate the LF wheel.
- Does the LF wheel rotate?
- Yes : TRIGGER all active commands OFF. GO to J5.
- No : INSTALL a new HCU. TURN the ignition switch from OFF to ON. REPEAT the ABS self-test. If any DTCs are retrieved, REFER to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If no DTCs are retrieved, CARRY OUT a drive test above 15 km/h (9 mph), then REFER to the SYMPTOM CHART .
- J5 CHECK ABS INLET AND OUTLET VALVE (CLOSED POSITION)
- Apply moderate brake pedal effort.
- Have an assistant attempt to rotate the LF wheel.
- Does the LF wheel rotate?
- Yes : INSTALL a new hydraulic control unit (HCU). REPEAT the self-test.
- No : REPEAT this procedure (beginning with Step J2) for the RF, LR and RR wheels using the appropriate active commands. If no failure occurs the system is operating normally.