38
Y
N
Y
N
Diagnosis on brake lamp failure in illumination
Diagnosis on power shortage of battery
Brake lamp failure
in illumination
Disassemble the cover of brake lamp and check
whether the circuit board is burnt.
Replace the circuit
board of brake lamp
Use a lead wire to short-circuit two terminals or two terminal pins
of brake lamp switch.
The brake lamp is not
light.
The brake lamp is light.
Use a screwdriver or a lead wire to strike the
power lead of brake lamp with the earth;
check the spark.
Improper adjustment of
brake lamp switch or bad
contact inside.
Spark available
No spark
Short circuit or open circuit between the brake lamp
switch and the brake lamp.
Short circuit or open circuit between the ignition switch or
brake lamp switch.
Power shortage of
battery
Check whether the brake
lamp is always light.
Adjust or replace the brake
lamp switch.
Leakage current is lower than
the required value.
Leakage current is higher than the required
value. (Normally, the leakage current is
required to be no more than 1mA.)
Turn the ignition switch to “OFF” position; disassemble the negative cable from
the battery and connect the negative/positive electrode of ampere meter to the
negative/positive terminal of battery; check leakage current.
