LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 1998 >> Mark VIII Base >> Repair and Diagnosis >> Brakes >> Traction Control >> Anti-Lock Brake System >> Symptom Tests >> Test D: Poor Vehicle Tracking During Abs Function
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test D: Poor Vehicle Tracking During Abs Function

  1. Turn air suspension switch off. Air suspension switch is located on left side of trunk. Raise vehicle on hoist. Bleed brake system. See BLEEDING BRAKE SYSTEM  . Remove vehicle from hoist, turn air suspension switch on and road test vehicle. If vehicle tracks poorly during ABS operation, go to next step. If vehicle tracks properly, system is functioning properly.
  2. Turn air suspension switch off. Air suspension switch is located on left side of trunk. Turn ignition on. Connect New Generation Star (NGS) tester (007-00500) to Data Link Connector (DLC). DLC is located under dash, on right side of steering column. Raise vehicle. Set transmission selector in Neutral and ensure all wheels turn freely. Enter active command ABS OUTPUT CONTROL. Trigger active command PMP MOTOR ON for 4 seconds. This requires trigger to be pressed twice. Each press activates motor for 2 seconds. Apply moderate pressure on brake pedal. If left front wheel will not rotate, go to next step. If left front wheel rotates, replace ABS Hydraulic Control Unit (HCU) and retest system.
  3. Trigger LF INLET and LF OUTLET ON. Using breaker bar, have assistant attempt to turn left front wheel within 2 seconds of each trigger press. If wheel does not turn, go to step 10)  . If wheel turns, go to next step.
  4. Enter active command ABS OUTPUT CONTROL. Trigger active command PMP MOTOR ON for 4 seconds. This requires trigger to be pressed twice. Each press activates motor for 2 seconds. Apply moderate pressure on brake pedal. If right front wheel will not rotate, go to next step. If right front wheel rotates, replace ABS Hydraulic Control Unit (HCU) and retest system.
  5. Trigger RF INLET and RF OUTLET ON. Using breaker bar, have assistant attempt to turn right front wheel within 2 seconds of each trigger press. If wheel does not turn, go to step 10)  . If wheel turns, go to next step.
  6. Enter active command ABS OUTPUT CONTROL. Trigger active command PMP MOTOR ON for 4 seconds. This requires trigger to be pressed twice. Each press activates motor for 2 seconds. Apply moderate pressure on brake pedal. If left rear wheel will not rotate, go to next step. If left rear wheel rotates, replace ABS Hydraulic Control Unit (HCU) and retest system.
  7. Trigger LR INLET and LR OUTLET ON. Using breaker bar, have assistant attempt to turn left rear wheel within 2 seconds of each trigger press. If wheel does not turn, go to step 10)  . If wheel turns, go to next step.
  8. Enter active command ABS OUTPUT CONTROL. Trigger active command PMP MOTOR ON for 4 seconds. This requires trigger to be pressed twice. Each press activates motor for 2 seconds. Apply moderate pressure on brake pedal. If right rear wheel will not rotate, go to next step. If right rear wheel rotates, replace ABS Hydraulic Control Unit (HCU) and retest system.
  9. Trigger RR INLET and RR OUTLET ON. Using breaker bar, have assistant attempt to turn right rear wheel within 2 seconds of each trigger press. If wheel does not turn, go to step 10)  . If wheel turns, system is operating normally.
  10. Retrieve any stored DTC(s). If any DTC(s) are stored, service in numerical order. See ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE DTC DEFINITIONS  . If no DTC(s) are stored, replace HCU and retest system.
scientia non olet · About LEMON Manuals