B1266 Instrument panel system communication bus short to battery

What does B1266 mean on a Toyota?

B1266. Instrument panel system communication bus short to battery. The bus sees battery voltage it should not. This Toyota-enhanced code applies to Toyota, Lexus and Scion models that use this code.

Common causes of B1266

• Open or short in the instrument panel system communication bus
• Loose or corroded connector at the instrument panel system communication bus
• Damaged harness on the instrument panel system communication bus
• Failed instrument panel system communication bus
• Low system voltage

How to fix B1266

1. Confirm the code and read freeze frame data
2. Check battery voltage and the charging system
3. Inspect and reseat the instrument panel system communication bus connector
4. Test the instrument panel system communication bus for opens and shorts
5. Replace the instrument panel system communication bus only after the circuit tests fail