This procedure covers the replacement of the horn relay in a 2018-2024 Toyota Camry with a 2.5L I4 engine, located in the engine compartment fuse/relay box.

Warnings

Tools required

Parts

• Horn relay × 1 — Use OEM specification - Toyota 90987-02028 or equivalent

Preparation

1. Park vehicle on level surface and apply parking brake
2. Turn ignition OFF and remove key from vehicle
3. Open hood and secure with prop rod
4. Locate the engine compartment fuse/relay box on the driver's side near the battery
5. Allow engine to cool if recently operated

Procedure

1. 1

   Disconnect negative battery terminal
   Using a 10mm socket, loosen the negative battery terminal bolt and disconnect the negative cable from the battery. Move the cable away from the terminal to prevent accidental reconnection.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
2. 2

   Remove fuse box cover
   Release the clips on the engine compartment fuse/relay box cover by pressing the tabs and lifting upward. Set the cover aside with the relay diagram facing up for reference.
3. 3

   Identify horn relay location
   Locate the horn relay using the diagram on the underside of the fuse box cover or on the box itself. The horn relay is typically labeled 'HORN' or 'H-LP RLY' and is often in the front row of the relay box. Verify relay position before removal.
4. 4

   Remove old horn relay
   Using a relay puller tool or needle-nose pliers, grasp the horn relay firmly and pull straight up with even pressure. Rock gently side-to-side if needed, but do not bend the relay terminals. Remove the relay from its socket.
   ⚠Pull straight up to avoid bending or damaging the socket terminals
5. 5

   Inspect relay socket
   Examine the relay socket for corrosion, damage, or debris. Check that all socket terminals are straight and undamaged. Clean any corrosion with electrical contact cleaner if necessary. Verify the socket is dry before proceeding.
6. 6

   Install new horn relay
   Align the new horn relay with the socket, ensuring proper orientation by matching the relay terminal layout with the socket configuration. Press the relay firmly into the socket until it is fully seated and cannot be pulled out without deliberate force. Verify all terminals are engaged.
7. 7

   Reinstall fuse box cover
   Position the fuse box cover over the relay box, aligning the clips with their mounting points. Press down firmly on all corners until all clips engage with an audible click.
8. 8

   Reconnect negative battery terminal
   Reconnect the negative battery cable to the negative battery terminal. Using a torque wrench, tighten the terminal bolt to specification. Ensure the connection is secure but do not overtighten.
   ⚠Do not overtighten battery terminal bolts as this can damage the terminal or battery post
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure fuse box cover is properly secured with all clips engaged
2. Verify battery terminal is tight and secure
3. Close hood after verification testing is complete

Verification

• Turn ignition to ON position without starting the engine
• Press the horn button on the steering wheel to verify horn operation
• Horn should sound clearly and consistently when button is pressed
• If horn does not operate, verify relay is fully seated and check horn fuse
• Verify no warning lights are illuminated on the instrument cluster
• Test horn multiple times to ensure consistent operation

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