Mitsubishi Electric 55624R(S)-MF Service Manual page 167

Problem
The system is not disarmed
when, while armed, a left and/or
right door is opened by using the
key.
(Alarm sounds in error.)
2. ACTIVATION/DEACTIVATION RELATIONSHIP
Problem
There is no alarm when, as an
alarm test, a door is opened
without using the key.
(The arming and disarming are
normal, however, and the alarm
is activated when the trunk lid or
hood is opened.)
There is no alarm when, as an
alarm test! the trunk lid is
opened wtthout using the key.
(The alarm is activated, howev-
er, by the opening of a door.)
There is no alarm when, as an
alarm test, the hood is opened
from within the vehicle.
ECU harness connector discon-
vithin the vehicle.
The headlights can, however,
THEFT-ALARM SYSTEM - Troubleshooting
Probable cause
Damaged or disconnected
wiring of key cylinder switch
Malfunction of the ECU
Probable cause
switch
Malfunction of the electro-
Damaged or disconnected
wiring of trunk lid switch
switch
Malfunction of the ECU
Damaged or disconnected
wiring of hood switch input
circuit
Malfunction of the hood
switch
Malfunction of the ECU
There is a short-circuit of the
a short-circuit of the key-
reminder switch at the same
time.
Damaged or disconnected
wiring of headlight relay or
horn relay drive circuit
Damaged or disconnected
wiring of diode
Malfunction of the ECU
Check method Remedy
If a malfunction is indi- Repair the harness or
replace the key cylinder.
checking the input sig-
nals, check by follow-
ing individual part and
the circuit check No. 7
procedures. (P.54-175)
Replace the ECU.
Check method Remedy
Repair the harness or
replace the door switch.
the circuit check No.4.
Replace the electronic
control unit.
If a malfunction is indi- Repair the harness or
replace the trunk lid
checking the input sig- switch.
nals, check by follow-
ing individual part and
the circuit check No. 8
procedures. (P.54-176)
Replace the ECU.
If a malfunction is indi- Repair the harness or
replace the hood switch.
checking the input sig-
nals, check by follow-
ing individual part and
the circuit check No.3
procedures. (P.54-171)
Replace the ECU.
Check by following in-
Repair the harness and
replace
circuit check No. 14 reminder switch.
procedures. (P.54-180)
Check by following in-
dividual part and the
circuit check No. 10, 12
procedures. (P.54-177,
178)
Replace the ECU.