Test B: The Horn Is Always On
PINPOINT TEST B: THE HORN IS ALWAYS ONNormal Operation
The battery junction box (BJB) supplies voltage to the horn relay (part of the smart junction box [SJB]) through circuit SBB02 (YE/RD). When the horn switch (part of the steering wheel) is pressed, the switch closes and ground is applied from the steering wheel switch harness through the clockspring to the horn relay through circuit CRH02 (BU/WH). The horn relay is then energized, applying voltage to the horn through circuit CBP14 (VT/OG), enabling the horn to sound.
- DTC B1218 (Horn Relay Coil Circuit Short to Vbatt) - is a continuous and on-demand DTC that sets when the SJB detects a short to voltage on the horn relay coil circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Steering wheel switch harness
- Clockspring
- Horn switch (part of the steering wheel)
- SJB
B1-B4:
B4-B6:
