VTSS Test 4A - Repairing VTSS Horn Circuit
NOTE:
Perform VTSS TEST 1A
before proceeding with this test. For connector terminal identification, refer to CONNECTOR IDENTIFICATION
. For wiring diagrams, refer to WIRING DIAGRAMS
. Refer to ANTI-THEFT SYSTEM
article. After each repair, perform TEST VER-2A
.
CAUTION:
Always turn ignition switch to OFF position prior to disconnecting any module connector. Ensure all connectors are clean and tight.
- Turn ignition switch to on position. Press horn button. If horn does not sound, go to step 3). If horn sounds, turn ignition off. Disconnect Body Control Module (BCM) White 24-pin connector. BCM is located under left side of dash. See Figure in CHIME TEST 3A.
- Momentarily connect a jumper wire between terminal No. 13 (Gray/Orange wire) on BCM White 24-pin connector and ground. If horn does not sound, repair open in Gray/Orange wire. If horn sounds, replace BCM.
- Remove horn relay. Horn relay is located in power distribution center. Power distribution center is located in engine compartment. Using an ohmmeter, check resistance between component terminals No. 85 and 86 on horn relay. See Fig 1 . If resistance is less than 65 ohms or more than 90 ohms, replace relay. If resistance is more than 65 ohms or less than 90 ohms, go to next step.
- Using scan tool in voltmeter mode, measure voltage at terminal No. 86 on horn relay connector. If voltage is less than 10 volts, replace power distribution center. If voltage is 10 volts or more, go to next step.
- Connect a test light between terminals No. 85 (Gray/Orange wire) and No. 86 (Violet wire) on horn relay socket. Press horn button while observing test light. If test light does not flash when horn button is pressed, repair open in Gray/Orange wire. If test light flashes when horn button is pressed, go to next step.
- Connect a jumper wire between horn relay connector terminals No. 30 (Violet wire) and No. 87 (Dark Green/Yellow wire). If horn sounds, replace horn relay. If horn does not sound, go to next step.
- Disconnect connector from on both horns. Connect one horn connector with a jumper wire to ground. With scan tool in ohmmeter mode, measure resistance at terminal No. 87 (Dark Green/Yellow wire) on horn relay connector. If resistance is more than 5 ohms, repair open in Dark Green/Yellow wire. If resistance is 5 ohms or less, go to next step.
- Disconnect jumper wire. Using scan tool in ohmmeter mode, measure resistance at terminal No. 87 (Dark Green/Yellow wire) on horn relay connector. If resistance is less than 100 ohms, repair short in Dark Green/Yellow wire. If resistance is 100 ohms or more, replace horns.