2. Unexpected Pedal Action

WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK BRAKE PEDAL STROKE
Check brake pedal stroke. Is stroke excessively large?
1. Yes: Perform Preliminary Check. Refer to "PRELIMINARY CHECK ".
2. No: GO TO 2.
Fig 1: Checking Brake Pedal Stroke
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK CONNECTOR AND PERFORMANCE
1. Disconnect ABS actuator and electric unit (control unit) connector.
2. Check whether brake is effective.
  OK or NG
  1. Yes: GO TO 3.
  2. No: Perform Preliminary Check. Refer to "PRELIMINARY CHECK ".
CHECK WARNING LAMP INDICATION
Ensure warning lamp remains off while driving.

Is warning lamp turned off?
1. Yes: GO TO 4.
2. No: Carry out self-diagnosis. Refer to "SELF-DIAGNOSIS PROCEDURE ".
Fig 2: Checking ABS Warning Lamp Indication
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK WHEEL SENSOR
1. Check wheel sensor connector for terminal damage or loose connection.
2. Perform wheel sensor mechanical check.
  Is wheel sensor mechanism OK?
  1. Yes: Check ABS actuator and electric unit (control unit) pin terminals for damage and the connection of harness connector. Reconnect ABS actuator and electric unit (control unit) harness connector. Then retest.
  2. No: Repair.