2022 Hyundai IONIQ 5

Hyundai IONIQ 5 U0100 BMS Communication Loss — GWM Module Corruption After OTA

U0100 U0073 C1611 Published 2025-02-10 Updated 2025-02-10
Hyundai IONIQ 5 U0100 BMS GWM OTA update communication E-GMP

2022 Hyundai IONIQ 5 presented with multiple U-codes and inability to enter Ready state 48 hours after an over-the-air software update. U0100 against BMS, U0073 CAN bus off, C1611 against GWM. Root cause: incomplete OTA update corrupted the Gateway Module routing table.

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The Problem
2022 Hyundai IONIQ 5 AWD (36,100 miles) would not enter Ready state. Multiple fault codes stored. Customer reported accepting an OTA update two days prior, after which the car showed 'EV System Check' and refused to start. U0100 (Lost Communication with BMS), U0073 (CAN Bus Off), and C1611 (GWM Internal Fault) confirmed via GDS2.
Diagnostic Procedure
  1. 1. Confirm fault codes. Three codes all point toward network communication breakdown. GWM (Gateway Module) manages CAN routing between all vehicle networks.
  2. 2. Check OTA update log via BlueLink portal. Update 23.01.4 was downloaded and installation began but did not complete — power interruption during install (customer reports 12V charger was disconnected that night).
  3. 3. Attempt GWM communication via GDS2 — module responds erratically. Routing tables partially updated, creating CAN routing conflicts that prevent BMS from appearing on the network.
  4. 4. Perform GWM forced software reinstall via GDS2 online programming. Full 23.01.4 installation completes successfully (17 minutes).
  5. 5. After reflash, clear all codes. BMS now visible on network. U0100 and U0073 gone.
  6. 6. Ignition cycle: vehicle enters Ready state normally. All systems check out.
  7. 7. 15-mile test drive including DC fast charge session — no faults.
Resolution & Root Cause
GWM reflashed with complete OTA software version. BMS communication restored, all faults cleared.
💡 Key Lesson
Never interrupt power to a Hyundai/Kia E-GMP vehicle during an OTA update — not even the 12V charger. Partial installation corrupts the GWM routing table, causing cascading U-codes that look like catastrophic network failure. The fix is not module replacement; it's completing the interrupted software install via GDS2 with a stable power supply.
About This Case

This case was solved remotely by an HVDesk specialist with 15+ years of hands-on experience across major EV platforms including Tesla, Hyundai/Kia, Volkswagen ID series, BMW i-series, and Ford EVs. The procedure was provided as structured remote support to an independent auto repair shop.