TM
9-2320-387-24-l
INSTRUMENTS
CIRCUIT
DIAGNOSTIC
FLOWCHART
1
TES T OPTIONS
NONE
BLEED BRAKE SYSTEM. DOES THE
LIGHT STAY ON?
POSSIBLE
PROBLEMS)
REASON
FOR QUESTION
If the lamp stays on, it could be
that the hydraulic brake system
has a fault and might require
bleeding.
PROPORTIONING
VALVE
WIRING
PARKING BRAKE SWITCH
BOX
BRAKE WARNING
PRESSURE
SWITCH
TEST OPTIONS
BRAKE WARNING
LIGHT WON’T GO OFF
-
I
ZHECK PROPORTIONING
VALVE
‘OR PROPER OPERATION.
(GO
l-0 B-7 PAGE 2-428). IS PROPOR-
rlONlNG VALVE OPERATING
‘ROPERLY?
NONE
REASON
FOR QUESTION
If the lamp stays on after
bleeding the brake system, the
proportioning
valve could be
malfunctioning.
1
POSSIBLE
PROBLEMS
PROPORTIONING
VALVE
WIRING
PARKING BRAKE
SWITCH BOX
BRAKE WARNING
PRESSURE
SWITCH
r
.
3RAKE WARNING
LIGHT WON’T GO OFF
3
1
1
TEST OPTIONS
VISUAL
IISCONNECT
WIRE 67A AND 67B
FROM BRAKE WARNING PRESSURE
SWITCH, AND WIRE 67C FROM
PARKING BRAKE SWITCH. DISCON-
NECT THE PCB BODY HARNESS
CONNECTOR. CONNECT A JUMPER
WIRE BETWEEN WIRES 67A AND
67B. DOES THE LIGHT GO OUT?
REASON
FOR QUESTION
If the lamp stays on with the
PCB, valve switch, and park
brake switch disconnected,
the
problem is in the wiring.
I
POSSIBLE
PROBLEMS
1
WIRING
PARKING
BRAKE SWITCH
BOX
BRAKE WARNING
PRESSURE
SWITCH
2-328