P0A9F Possible Causes
- Faulty HV battery assembly (HV battery temperature sensor)
- HV battery assembly harness is open or short-circuited
- Poor electrical connection of HV battery assembly circuit
- Faulty battery intelligent unit
What Does It Mean?
How to Fix Code P0A9F
Check the “possible causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
P0A9F Possible Symptoms
Check engine light illuminated (or service engine soon warning light)
P0A9F Meaning
The battery temperature sensors are provided at 3 locations of the HV battery. The thermistor resistance, built into each battery temperature sensor, varies according to changes in HV battery temperature. The lower the battery temperature, the higher the thermistor resistance. Conversely, the higher the temperature, the lower the resistance. The battery intelligent unit uses the battery temperature sensors to detect HV battery temperature and sends the detected value to the power management control ECU. Based on the detection results, the power management control ECU controls the fan. (The fan starts when the HV battery temperature exceeds a predetermined level.)