I have a 2010 prius, just pulled the battery to replace a few cells that were bad. Have replaced cells before with no issue. The car was running before. Put the battery back and U029A and no start. Replaced the voltage ecu, no change. Replaced, the junction block with the relays - no change.Replaced the wiring harness at the voltage sensor side no change. Checked all the cabin and engine fuses nothing looks blown. At a loss as to what i messed up when i put the battery back in. Please help.
The trouble code for the orange switch is P0A0D. U029A is about the communication link between the power management control ECU (behind the glove box) and the smart voltage sensor inside the battery. Looks like you've replaced that sensor once with no change, so wiring and connections could be next to check. There are troubleshooting steps for U029A in the repair manual. Toyota Service Information and Where To Find It | PriusChat
