Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Horn relay circuit
Toyota Corolla (E120): Horn relay circuit
Other materials:
How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 5, 7, 10.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Connect hand–held tester to dlc3
Hint:
if the display indicates a communication fault in the tool, inspect dlc3.
4 Check dtc and freeze frame data
Hint:
record or pr ...
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 ...
Monitor description
While the engine is being cranked, the battery positive voltage is applied to
terminal sta of the ecm.
If the ecm detects the starter control signal (sta) while the vehicle is
driving, it will conclude that there is
a fault in the starter control circuit. The ecm will turn on the mil and a d ...


