B1206: EIC Switch-1 Assembly Circuit Open
What does B1206 mean?
B1206 is a body electronics fault indicating that the control module has detected an open circuit in the EIC Switch-1 Assembly circuit. An open circuit means electrical continuity has been broken somewhere in the loop, so the module is sending a signal out but getting nothing back. The EIC switch circuit forms part of the body electronics network that manages various interior and instrument functions depending on the vehicle.
The most likely causes are a broken or disconnected wire in the switch assembly harness, a failed switch component, or a corroded connector that has broken the circuit path. Open circuits are usually straightforward to trace with a multimeter: check for continuity along the circuit from the module connector back to the switch assembly, looking for the point where continuity disappears.
At medium severity, this fault will likely disable the function controlled by that switch or trigger a warning on the instrument cluster. It is unlikely to leave you stranded, but ignoring it means losing the affected feature indefinitely. A wiring inspection followed by connector cleaning or switch replacement will resolve most cases.
Symptoms you may notice
- Check engine light (MIL) illuminated on dashboard
- Intermittent warning lights
- Erratic gauge readings
Estimated repair cost
Typical range in Australia (parts + labour)
Common causes
- Damaged or corroded wiring harness
- Loose or disconnected electrical connector
- Failed body electronics sensor or actuator
- Blown fuse in the related circuit
- Poor ground connection
What should you do?
Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.
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Code B1206 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.