Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 390

Code No.66 Brake vacuum sensor system
Range of check
Ignition switch: ON
Set conditions
Sensor output voltage is 4.8 V or more.
or
Sensor output voltage is 0.2 V or less.
Measure at the brake vacuum sensor
connector A-70.
Connect the connector. (Use test
harness MB991348)
Voltage between 1 and earth
(After the engine is turned off
from idle speed, turn on the
ignition switch, and then depress
the brake pedal several times.
OK: Voltage increases.
OK
Check the following connectors:
A-70, B-29
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the brake vacuum
sensor.
OK
Replace the engine-ECU.
GDI –
Troubleshooting
NG
Measure at the brake vacuum sensor
connector A-70.
Disconnect the connector, and
measure at the harness side.
Voltage between 3 and earth
(Ignition switch: ON)
OK: 4.8 – 5.2 V
Continuity between 2 and earth
OK: Continuity
OK
Check the following connector:
A-70
OK
Check trouble symptom.
NG
Repair
NG
Repair
Probable cause
Malfunction of the brake vacuum sensor
Improper connector contact, open circuit or
short-circuited harness wire of the brake vacuum
sensor
Malfunction of the engine-ECU
NG
Check the following connectors:
B-29, B-31
Check trouble symptom.
Check the harness wire between the
engine-ECU and the brake vacuum
sensor.
NG
Repair
Replace the engine-ECU.
NG
Check the harness wire between the
engine-ECU and the brake vacuum
sensor.
Replace the brake vacuum sensor.
13A-31
OK
NG
Repair
NG
OK
NG
Repair
OK
NG
Repair