Horn: Testing and Inspection

DIAGNOSIS AND TESTING

Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

1. Disconnect the wire harness connectors from the horn terminal connectors. Check for continuity between the horn ground circuit connector and a good ground. There should be continuity. If OK, go to 2. If not OK, repair the open ground circuit to ground as required.
2. Check for battery voltage at the horn output circuit connector. There should be zero volts. If OK, go to 3. If not OK, repair the shorted horn output circuit between the horn and the Totally Integrated Power Module (TIPM) as required.
3. Depress the horn switch. There should now be battery voltage at the horn output circuit connector for the horn. If OK, replace the faulty horn. If not OK, use a diagnostic scan tool and the appropriate diagnostic information for further diagnosis of the TIPM, the Local Interface Network (LIN) master node of the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN), the LIN slave node of the speed control switch pod, the horn switch, the LIN data bus and the CAN data bus.