Grand Cherokee 2WD Limited V8-4.7L (2002)
Brake Warning Indicator: Testing and Inspection
DIAGNOSIS AND TESTING - RED BRAKE WARNING LAMP
The red warning lamp illuminates when the parking brake is applied or when the fluid level in the master cylinder is low. It will also illuminate at start
up as part of a bulb check.
If the light comes on, first verify that the parking brakes are fully released. Then check pedal action and fluid level. If a problem is confirmed, inspect
the brake hydraulic system for leaks.
A red warning lamp with a amber warning lamp may indicate a electronic brake distribution fault.
The diagnosis found here addresses an inoperative park brake indicator condition. If there are problems with several indicators in the instrument
cluster, refer to Instrument Cluster Diagnosis and Testing. If the brake indicator stays ON with the ignition switch in the ON position and the park
brake released, or comes ON while driving. If no brake system problem is found, the following procedures will help to locate a shorted or open circuit,
or a faulty park brake switch input. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, DRIVER AIRBAG, PASSENGER AIRBAG, SIDE CURTAIN
AIRBAG, FRONT IMPACT SENSOR, SIDE IMPACT SENSOR, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE SYSTEM
CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO
DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Indicator Illuminates During Bulb Test, But Does Not When Park Brake Applied
1. Disconnect and isolate the battery negative cable. Disconnect the instrument panel wire harness connector for the park brake switch from the
switch terminal. Apply the parking brake. Check for continuity between the park brake switch terminal and a good ground. There should be
continuity If OK, go to Step 2. If not OK, replace the faulty park brake switch.
2. Disconnect the instrument panel wire harness connector for the instrument cluster from the cluster connector receptacle. Check for continuity
between the red brake warning indicator driver circuit cavities of the instrument panel wire harness connector for the park brake switch and the
instrument panel wire harness connector for the instrument cluster. There should be continuity If not OK, repair the open red brake warning
indicator driver circuit between the park brake switch and the instrument cluster as required.
Indicator Remains Illuminated - Brake System Checks Ok
1. Disconnect and isolate the battery negative cable. Disconnect the instrument panel wire harness connector for the park brake switch from the park
brake switch terminal. Check for continuity between the terminal of the park brake switch and a good ground. There should be no continuity with
the park brake released, and continuity with the park brake applied. If OK, go to Step 2. If not OK, replace the faulty park brake switch.
2. Disconnect the instrument panel wire harness connector for the instrument cluster from the cluster connector receptacle. Check for continuity
between the red brake warning indicator driver circuit cavity of the instrument panel wire harness connector for the park brake switch and a good
ground. There should be no continuity. If not OK, repair the shorted red brake warning indicator driver circuit between the park brake switch and
the instrument cluster as required.
