Horn System: Inspection

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Inspect horn switch :
1. Disconnect the negative (-) terminal from the battery.
2. Remove the left and right covers from the steering wheel.
3. Using a Torx socket wrench, loosen the 2 bolts.
4. Pull up the horn pad and place it on the steering column, as shown.
5. Disconnect the connector from the slip ring.
  
  Fig 1: Locating Slip Ring Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Check that no continuity exists between terminal 6 of the connector and body ground.
7. Check that continuity exists between terminal 6 of the connector and body ground when the horn contact plate is pressed against the steering spoke assembly.
  
  Fig 2: Locating & Testing Terminal 6 Continuity
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If continuity is not as specified, repair or replace the steering wheel or wire harness as necessary.
8. Install the horn pad in place and using a Torx socket wrench, torque the 2 bolts.
  Torque: 7.1 N.m (72 kgf.cm, 62 In.Lbs)
9. Install the left and right covers.
10. Connect the negative (-) terminal to the battery.
Inspect horn operation:
Connect the positive (+) lead from the battery to the terminal and negative (-) lead to the horn body and check that the horn blows.

Fig 3: Testing Horn
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If operation is not as specified, replace the horn.
Inspect horn switch circuit. See HORN CIRCUIT .
Inspect horn relay continuity :

Fig 4: Identifying Horn Relay Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 5: Horn Relay Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If continuity is not as specified, replace the relay.
Inspect horn relay circuit . See FUSES & CIRCUIT BREAKERS .