Mitsubishi Electric 55624R(S)-MF Service Manual page 177

10. THEFT-ALARM HORN RELAY POWER-SUPPLY CIRCUIT
Battery
alarm
horn
11. HORN ACTIVATION CIRCUIT
Sub fusible link @I
Theft-
alarm
horn
THEFT-ALARM SYSTEM
Description of operation
Power voltage is always supplied to the theft-alarm horn relay.
Checking the theft-alarm horn relay power-supply circuit
(Disconnect the theft-alarm horn relay)
terminal voltage
Checking individual part:
Theft-alarm horn relay - Refer to P.54-105.
control unit
(electronic
control unit)
Description of operation
The ECU transistor is turned ON if the vehicle door, etc. are
opened without use of the key.
This energizes the theft-alarm
theft-alarm horn.
Checking the theft-alarm horn activation circuit (Disconnect the
connector of the ECU, then short-circuit terminal No. 2 (YL line),
and activate the theft-alarm horn relay)
1
ETACS
control unit
(electronic
2
u n i t )
3
Judgement
Check object
Battery
positive
voltage
Judgement
Check object
Normal
function
Theft-alarm horn re- Battery o v
lay terminal voltage
(l-Ground)
voltage
Theft-alarm horn ter-
Battery OV
voltage
Theft-alarm horn ter-
alarm alarm
(Ground side horn horn
sounds doesn't
sound
Battery
positive
voltage
I
Cause
ov Sub fusible link @
sub fustble
blown
link
Damaged or discon- Repair the
harness
horn
relay to activate the
Cause Remedy
Malfunction of the Check the
theft-alarm horn relay theft-alarm
horn relay
(Refer to
Harness damaged or Repair the
disconnected harness
Replace the
theft-alarm horn theft-alarm
Damaged or discon- Repair the
harness
ground circuit
I