Did you find out anything?I'm an ASE master technician and my wife had the same issue with her Kia Optima Hybrid. No brakes at all and almost crashed. There was no failsafe for the brakes. Luckily she was smart enough to use the parking brake to slow down and coast to the shoulder. I researched it and replaced the HPU ( Hydraulic Pressure Unit). So far the brakes have not acted up but I'm still getting the Check Brakes warning and the red brake light is on. The codes that I'm getting now are different than the original code I had. Original code was C1237, new codes are C1702 and C1236. When I installed the HPU the service manual said the only other thing I had to do was calibrate the brake pressure sensor which I did. I also bled the brakes a few times. Brake pedal is normal. I think the HPU has to be programmed by the dealership. Everytime I have replaced a brake module or Engine control module they have to be programmed. My Wife is taking the car to the Kia dealership tomorrow for a recall and we are going to get or see if they can program the HPU. I will let you know how it goes!
I’ve got a 2017 Optima hybrid PHEV and about every 4-5 weeks it goes crazy with the following codes while driving
- C164608 CAN Message Failure
- C224308 Gear Fault
- C135B08 HCU Torque Control Unavailable for SCC