DTC P0A09-591: DC / DC Converter Status Circuit Low Input [11/2016 - ]: Description
WARNING: This page is about a different car, the 2019 Toyota Highlander, 2018 Toyota Highlander, and 2017 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
The DC/DC converter varies output voltage based on voltage change signals (VLO signal line) received from the hybrid vehicle control ECU assembly.
If the vehicle is being driven with an inoperative DC/DC converter, the voltage of the auxiliary battery will drop, which will prevent the continued operation of the vehicle. Therefore, the hybrid vehicle control ECU assembly monitors the operation of the DC/DC converter and alerts the driver if it detects a malfunction.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Warning Indicate |
|---|---|---|---|---|---|
| P0A09-591 | DC / DC Converter Status Circuit Low Input | Open or short to ground in the signal line of DC/DC converter (VLO) (1 trip detection logic) |
|
Does not come on | Master Warning Light: Comes on |