Computer Failure Problems of Toyota Highlander

I sent a letter to Toyota motor sales USA after being refused service at a local dealer to resolve a safety issue, with no reply. While pressing brake when starting I got a couple of error messages that said to contact a Toyota dealer. I did some very detailed research into this problem and what others had encountered. I found the errors would only show when the 12 volt battery was getting low on charge. The brake booster pump is one of the suspect items draining the battery because it continues to run long after the vehicle is parked. Since I don't have the tools to check the current draw on this or if it is even supposed to run long after the vehicle is shut off, I wanted my Toyota dealer to check this. There is a " customer support program notification - zkc" related to this for the brake actuator assembly and brake booster pump assembly. I specifically requested that they check out the electrical component of the brake booster pump even if not covered by warranty. I also told them about the errors only occurring on a low 12 volt battery charge. Their diagnosis showed an error code of poaa6 and only the warning lights and error message in the car display. They not only decided this was not covered by warranty but also ignored my specific request to test the brake system at my expense. No attempt at checking brakes or 12 volt charging system. I was told they would have to open the inverter to check that with the known outcome that this inverter is not repairable but would have to be replaced at a cost of $10,000. . New 12v battery installed. Computers can malfunction if not given the design operating voltage! I have trouble believing that there is a "hybrid battery voltage system isolation fault" due to the fact that the on board computer does not report this message when operating on a fully charged 12 volt system - in other words operating under normal conditions.

See all problems of the 2008 Toyota Highlander 🔎.