What does it mean?
B1284 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Windshield Wiper Switch HIGH Position Circuit Malfunction .
Symptoms
- Wipers will not run on high speed while low and intermittent still work
- Wipers run at high speed continuously as soon as they are switched on
- Blades briefly run fast then drop back to low speed
- Wiper system warning or message on the display
- Poor visibility in heavy rain
Likely causes
- Worn or oxidised HIGH contacts in the wiper stalk, this position is used least and oxidises first
- Open circuit in the HIGH signal wire or its connector
- Short to ground or to battery voltage on the HIGH circuit
- Water damage inside the steering column switch pack
- High-speed relay or wiper motor high-speed winding fault on systems that monitor feedback
- Corrosion at the wiper motor connector under the cowl, an area that stays wet
- Controlling module input stage failure
How to fix it
- Check the switch state data in live data while selecting the HIGH position
- Back-probe the HIGH circuit and confirm the voltage changes state with the stalk
- Disconnect the switch and test the wire for a short to ground and a short to battery
- Inspect the wiper motor connector under the cowl and the column loom for moisture and chafing
- Feed the wiper motor directly on its high-speed circuit to separate a motor fault from a switch fault
- Replace the combination switch when the HIGH contact does not make cleanly
- Repair the wiring, and replace the controlling module only as the final step