Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Horn relay circuit
Toyota Corolla (E120): Horn relay circuit
Other materials:
Circuit description
The shift solenoid valve sl is turned ”on” and ”off” by signals from the ecm
in order to control the hydraulic
pressure operation, the lock–up relay valve, which then the controls operation
of the lock–up clutch.
Fail safe function:
if the ecm detects a malfunction, it turns the ...
Battery
Check the battery as follows.
■ Battery exterior
Make sure that the battery terminals are not corroded and that there are no
loose connections, cracks, or loose clamps.
1 Terminals
2 Hold-down clamp
■Before recharging
When recharging, the battery produces hydrogen gas which is ...
How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Warning light check
4 The dtcs check (present and past dtcs)
5 The dtcs chart
6 Circuit inspection
7 Repair
8 Clear the dtcs (present and past dtcs)
9 The dt ...


