Toyota Corolla (E120) 2002–2008 Repair Manual / Communication system
Toyota Corolla (E120): Communication system
Horn system
Location

Problem symptoms table

Inspection
1. Inspect low pitched horn assy

- Connect the positive (+) lead from the battery to the terminal and the negative (–) lead to the horn body, and check that the horn blows.
If the result is not as specified, replace the horn.
2. Inspect horn relay assy (marking: horn)

- Remove the horn relay from the engine room j/b.
- inspect the horn relay continuity.
Standard:

If the result is not as specified, replace the relay.
Other materials:
On–vehicle inspection
1. Inspect air–fuel ratio compensation system
Hint:
you can also check the system by choosing ”data monitor”,
then ”o2 sensor output voltage” on the monitor of the
hand–held tester.
Connect the hand–held tester to the terminal 23 (ox1a)
@ 7 (e1) and 21 (ox1b) @ 7 (e1) of ...
Source voltage drop
The srs is equipped with a voltage–increase circuit (dc–dc converter) in the
airbag sensor assy center
in case the source voltage drops.
When the battery voltage drops, the voltage–increase circuit (dc–dc converter)
functions to increase the
voltage of the srs to normal voltage.
...
Inspection procedure
1 Inspect ecm(+b voltage)
Turn the ignition switch on.
measure the voltage between the terminals of the e4 and
e6 ecm connectors.
Standard:
2 Check harness and connector(ecm – body ground)
Disconnect the e4 ecm connector.
check the resistance between the wire ...


