Wagoneer L6-242 4.0L VIN M FI (1988)
Braking Sensor/Switch: Description and Operation
Fig. 15 Brake Switch
Fig. 16 Parking Brake Circuitry
BRAKE SWITCH
The brake switch is located on the brake pedal linkage (fig. 15). When the brake switch closes it sends 12 Volts to the brake lights. In addition, it
sends 12 Volts to the ABS brake Electronic Control Unit (ECU) (fig. 16). The ECU does not depend on current flow to the brake lights for this
signal.
This input is used by the ECU to anticipate an ABS Cycle. However, no ABS system modulation will occur without this signal.