P0A91 - OBD II Trouble Code

Our automotive experts have put together the following information about the P0A91 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P0A91 code.

OBD II Fault Code

• OBD II P0A91

OBD-II Code Engine may not start is defined as a Drive Motor "B" Performance

Toyota's Hybrid System uses two "Motor Generators" (MG1 and MG 2) to converter high voltage to mechanical energy (movement). The two MG units are used to start the gasoline powered engine and act as the transmission. If the High Voltage control module detects an issue with MG1 or MG2, it will store code P0A91.

Engine may not start Symptoms

• Engine may not start
• Vehicle may be immovable

Common Problems That Trigger the P0A91 Code

• Hybrid vehicle generator failure
• Inverter/converter assembly failure