2006 Toyota Highlander Hybrid – ABS Pump Runs Frequently With C1391
- Aug 15
- 1 min read
Updated: Aug 15
CUSTOMER CONCERN
Customer states the ABS pump cycles every few minutes and DTC C1391 is stored.
CAUSE
No external brake-fluid leak was present. Scan data showed accumulator pressure rising with the pump operating and dropping after shutdown, confirming an internal brake actuator leak.
CORRECTION
Remove and replace brake actuator assembly. Perform required brake-system bleed and actuator initialization.