P1631 Communication Error From ECM to VSC
What does P1631 mean on a Toyota?
P1631 — Communication Error From ECM to VSC. This Toyota-enhanced code applies to Camry, RAV4, Highlander with VSC.
Common causes of P1631
- Open ECM-to-VSC communication line
- Corroded skid control connector
- Failing skid control ECU
- Software mismatch after module replacement
- Intermittent network dropout
How to fix P1631
- Scan both ECM and skid control ECU
- Check network communication health
- Verify module calibrations match
- Inspect connectors
- Reflash or replace modules per findings