Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Horn relay circuit / Circuit description
Toyota Corolla (E120): Circuit description
When the tvip system is transferred from the armed state to the alarm sounding state, the tvip ecu switches on the horn relay so that it can sound the horns. The horn sounds in 0.4 Seconds interval.
Wiring diagram

Other materials:
Check short circuit
If the wire harness is ground shorted as shown in fig. 5,
Locate the section by conducting a resistance check with
the body ground in step (b).
Check the resistance with the body ground.
Disconnect connectors a and c and measure the
resistance between terminals 1 and 2 ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
Symptom does not occur (go to
step 5)
5 Symptom simulation
6 Dtc check
7 Dtc chart
8 Problem symptoms table
9 Circuit inspection
10 Confirmation test
End
...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove horn button assy
Place the front wheels facing straight ahead.
using a torx socket wrench (t30), loosen the 2 torx
screws until the groove along the screw circumference
catches on the screw ca ...


