Hello all, Recently took out the HV battery and replaced a few modules and now need to fix the brakes . After I purchased the car a month ago it barely made it home and the brakes were not working then ,well just under mechanical pressure with the ABS light on and the triangle on . I have several codes 2 which seemed to pop up after I charged the battery POA08 and POA09 . As for the brake system I have several codes as follows, C1252 Brake Booster Pump Motor on Time Abnormally Long C1256 Accumulator Low Pressure C1310 Malfunction in HV system C1345 Linear Solenoid Valve Offset Learning Undone Also have under EMPS U0121 Would it be a good idea to bleed the brakes and go from there and what else could I try ?
Those ABS codes are the sort of errors that can happen with a bad 12V battery. That is the first thing to sort out with these used Prii. Make sure the battery is completely charged, or replace it if old. If the 12V bus voltage is too low, then the brake pressure pump does not produce the torque it needs to restore the high pressure after use. That pump can come on even when the car is off.
Checked the battery using a youtube video and results were the same as the users new battery . I think the brakes was a ongoing issue and the po did tell me the computer assy skid control box was replaced with a used one . I also found the buzzer assy skid control part that I assume makes the beeping noise in the trunk . Also when using Techstream I cannot get any of the ABS reset programs to work such as the Linear Solenoid Valve offset Learning
DTC P0A08 means that the DC/DC converter is not working. Make the Prius READY and measure voltage across the 12V battery. If it is not ~13.8VDC then check the DC/DC 100A fusible link in the main relay/fuse box. It is located within the ~5" long clear and whitish plastic box. If the fusible link is OK then the DC/DC converter failed and the inverter must be replaced. Also check the operation of the inverter coolant pump - you should see fluid turbulence in the inverter coolant reservoir whenever the Prius is IG-ON or READY. You must have a correctly operating 12V bus before you worry about the brakes and skid control system. That system is very sensitive to the voltage level on the 12V bus.
You might also gain some insight to your car's history by logging online at Toyota.com owners portal. Just add the car using the vin number and get the service history from the dealer. If the previous owner went to the dealer with car problems, it might have been recorded on their records SM-N900P ?
Not much in the vehicle history . Also battery tested great . The 2 POA codes are not coming up anymore just the ABS problem . Could it be a bad Brake pump located next to the battery ?
Clear the skid control ECU DTC. Then if the same codes come back, the brake actuator probably needs to be replaced. That is located on the firewall, you need to remove the cowl tray that contains the windshield wiper motor for access.
Cleared the ECU several times before and they come right back . Brake actuator replacement in pictures | PriusChat Now I understand what the actuator does and how to replace it I will get a used one and replace it and go from there .
