Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Horn relay circuit / Inspection procedure
Toyota Corolla (E120): Inspection procedure
1 Check low pitched horn assy

- Connect the positive (+) lead from the battery to the terminal and negative (–) lead to the horn body, and check that the horn blows.


2 Check relay (marking: horn)

- Remove the relay from the engine room j/b.
- check the horn relay continuity, as shown in the illustration and table.
Standard:



3 Check wire harness (tvip ecu engine room j/b)

- Remove the horn relay from the engine room j/b.
- check the continuity between the terminals of the tvip ecu and engine room j/b connectors, as shown in the illustration and table.
Standard:

*: Horn relay terminal


4 Check wire harness (engine room j/b horn)

- Check the continuity between the terminals of the engine room j/b and horn connectors, as shown in the illustration and table.
Standard:

*: Horn relay terminal.


Check and replace tvip ecu
Other materials:
Circuit description
The vapor pressure sensor and the vsv for the canister closed valve (ccv) are
used to detect abnormalities
in the evaporative emission control system. The ecm decides whether there is an
abnormality in the evaporative
emission control system based on the vapor pressure sensor signal.
Dtc p0 ...
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
If dtc p0441 (purge flow), p0446 (vsv for ccv), p0451, p0452 or p0453
(evaporative pressure
sensor) is output with dtc p0442 or p0456, ...
Diagnosis system
Description
when troubleshooting obd ii vehicles, the only difference
from the usual troubleshooting procedure
is that you need to connect an obd ii scan tool complying
with sae j1987 or a hand–held tester to the
vehicle, and read off various data output from the
vehicle†...


