Jan 262019
 

2005 Chrysler Pacifica

ABS light keeps coming on and then off


ABS Light On

Generally speaking this has to do with the wheel speed sensors going out. They are mounted inside the wheel hub bearings.

2005-chrysler-pacifica-speed-sensor

View of the front speed sensor mounting screw (1), hub and bearing (2), routing clip (3) and front wheel speed sensor (4)

“The 05 and 06 models have a lot of issues with the wheel speed sensors for the abs system. A failing sensor will cause the symptoms that you are describing.
Because of excessively high failure rates, Chrysler has re-designed the sensors and for this reason it is necessary to replace all 4 sensors…………even if just one is bad.” Source: Chrysler Mechanic

Anti-Lock Brake System, Inspection

A visual inspection must always be performed to confirm the presence of aftermarket components, potential collision damage, or areas of concern.

The ABS module is self monitoring. The module will carry out a preliminary electrical inspection of the hydraulic pump motor by turning the pump ON for approximately 1/2 second either when the ignition switch is turned to the RUN position and the brake pedal is not pressed or when the vehicle is in motion and at vehicle speeds above 12 mph. The ABS module will also carry out a wheel speed sensor self-test by sending a reference voltage to all of the wheel speed sensors through their circuitry when the ignition switch is turned to the RUN position, with or without brake pedal application. If a fault is detected in the pump or wheel speed sensors, the ABS module will shut down and disable the anti-lock system. Normal power assisted braking, however, remains.

  1. Verify stop lamps operate correctly by applying and releasing brake pedal with ignition switch in OFF position.
  2. Verify that PRNDL operates correctly on instrument cluster.
  3. Visually inspect for obvious signs of mechanical or electrical damage.
  4. If an obvious cause for an observed or reported concern is found, correct cause if possible before proceeding.
  5. Connect a suitably programmed scan tool to vehicle DLC.
  6. Carry out network test.
  7. Clear continuous DTCs and carry out self-test diagnostics for ABS

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