I've been testing Toyota Prius on openpilot versions 0.9.8 and above (mainly for SDSU porting), and some users have reported a “horse riding” effect (alternating acceleration and deceleration).

After some careful testing, I found that if the DSU is completely disconnected, a cruise fault occurs. This led me to suspect the following:

• The issue may not be related to SDSU porting itself.
• The enableDsu implementation may have issues, which could be causing the cruise fault.
• There may be a longitudinal tuning issue specifically with the Toyota Prius (some SDSU users are Prius owners).

Questions

• Have you received any recent reports/logs from Toyota Prius owners running openpilot 0.9.8+ with longitudinal control enabled?
• Could you check if the enableDsu functionality might not be working as expected?

I’ve attached logs from two different Toyota Prius vehicles running with DSU disconnected for reference.

800808aede841985/00000000--d48b541b97
7594f32730b32394/00000002--4e37f9de1b