Toyota Corolla Repair Manual: Inspection procedure

1 Check low pitched horn assy

1. 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)

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

Standard:

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

1. Remove the horn relay from the engine room j/b.
2.  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)

1. 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