THEFT-ALARM SYSTEM
Troubleshooting
10. THEFT-ALARM HORN RELAY POWER-SUPPLY CIRCUIT
Battery
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)
Judgement
I
I
Check
Cause
harness
terminal voltage
Battery
positive
voltage
ov
Sub fusible link
blown
Damaged or
harness
the
sub
link
Repair the
harness
Checking individual part:
Theft-alarm horn relay Refer to
alarm
control unit
horn
(electronic
control unit)
11. HORN ACTIVATION CIRCUIT
Sub fusible link
Theft-
alarm
horn
ETACS
control unit
(electronic
c o n t r o l u n i t )
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
horn
relay to activate the
theft-alarm horn.
Checking the theft-alarm horn activation circuit (Disconnect the
connector of the ECU, then short-circuit terminal No. 2
line),
and activate the theft-alarm horn relay)
Check object
Judgement
Normal
function
Cause
Remedy
1
Theft-alarm horn
Battery
o v
Malfunction of the
Check the
lay terminal voltage
theft-alarm horn relay
theft-alarm
(l-Ground)
voltage
horn relay
(Refer to
2
Theft-alarm horn
Battery OV
Harness damaged or
Repair the
voltage
disconnected
harness
side
voltage
3
Theft-alarm horn
of the
Replace the
voltage
alarm
alarm
theft-alarm horn
theft-alarm
(Ground
horn
horn
sounds
doesn’t
sound
Battery
Damaged or
positive
wiring of
voltage
ground circuit
Repair the
harness
Revision