The most common causes of P1B03 include: Battery management system (BMS) malfunction; High voltage battery cell imbalance; Battery temperature sensor fault; High voltage contactor failure. A professional OBD-II scan tool is recommended for accurate diagnosis.

How do I fix P1B03 for Hyundai IONIQ 5?

Recommended steps to address P1B03: (1) Schedule service as soon as possible (2) Reduce driving speed and avoid long trips (3) Monitor for additional warning messages (4) Have the vehicle diagnosed by a certified technician. Always consult a qualified EV technician for high-voltage system repairs.

Is it safe to drive with P1B03?

Driving with P1B03 is not recommended for extended distances. Schedule service within a few days to prevent further damage. Monitor for any additional warning lights.

Hyundai IONIQ 5

P1B03

Warning

Auxiliary Battery Temperature Sensor Circuit Malfunction

Severity

Warning

What does P1B03 mean?

Fault code P1B03 means "Auxiliary Battery Temperature Sensor Circuit Malfunction". This is a Hyundai-specific EV diagnostic trouble code for the Hyundai E-GMP platform. It is classified as "battery" with a severity level of "warning". Applicable models: IONIQ 5, IONIQ 6, Kia EV6.

Possible Causes

Battery management system (BMS) malfunction
High voltage battery cell imbalance
Battery temperature sensor fault
High voltage contactor failure

Recommended Actions

1 Schedule service as soon as possible
2 Reduce driving speed and avoid long trips
3 Monitor for additional warning messages
4 Have the vehicle diagnosed by a certified technician

This code applies to all vehicles. View generic P1B03 information →