U04A6

Code

Generic U — Network/User

Invalid Data Received From Hybrid/EV Battery Interface Control Module F

Brand: Generic

Type: U — Network/User

Views: UK: 23 EN: 30 RU: 27

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Page language: EN

Faulty or intermittent CAN/LIN/ethernet network between BICM F and controller
Corrupted or out-of-spec messages from Battery Interface Control Module F (BICM F)
Open/shorted wiring, poor connector contact, or water damage
Module power or ground fault at BICM F
Software/firmware mismatch or module configuration error
Defective BICM F hardware

Hybrid/EV warning or battery system warning lamp(s)
Reduced power, limp-home mode, or disabling of electric drive/charging
Inability to read battery module data or missing battery pack parameters on scan tool
Intermittent or persistent communication DTCs in battery or powertrain modules
Vehicle may not start or switch to READY state

Retrieve all stored/active U and BMS-related codes and freeze-frame data with a capable diagnostic scanner
Check for other communication codes (U0100, U0121, etc.) and battery/pack subsystem codes
Visually inspect BICM F connector, wiring harness, and nearby components for damage or corrosion
Verify BICM F supply voltage and ground(s) with battery disconnected for safety and following HV procedures
Measure CAN high/low DC voltages with ignition ON (refer to service manual) and check for expected idle voltages (~2.5 V common-mode)
Scan for presence of BICM F on the network and verify message rates/IDs using a CAN bus monitor or diagnostic tool

CAN message presence: BICM F message ID(s) should be present on the bus (use manufacturer data to identify IDs)
Message frequency: BICM messages typically appear multiple times per second (example 5–100 Hz depending on message)
Expected data fields: SOC 0–100%, pack voltage within vehicle-specific range (consult manual), pack current within allowable ±range
CAN voltage idle: CAN_H ≈ 2.5–3.5 V, CAN_L ≈ 0.5–2.5 V (verify with service spec)
Message integrity: consistent payload length and valid checksum/CRC if used by the manufacturer

Record all codes and freeze-frame data. Do not clear codes yet; note conditions when code set.
Verify safety: follow high-voltage safety procedures before accessing high-voltage components or connectors.
Perform a visual inspection of BICM F connector/cable for corrosion, bent pins, water ingress, or physical damage.
With ignition ON (and HV systems safe/isolated per manual), measure module supply voltage and ground integrity at BICM F pins.
Use a diagnostic scanner or CAN bus monitor to confirm the BICM F is present on the network and transmitting expected messages; note missing, malformed, or intermittent frames.
Measure CAN_H and CAN_L voltages and check continuity and resistance across the bus termination (typically ~60 ohm across H-L with two 120Ω terminators).
Wiggle-test harness/connectors while monitoring messages to reproduce the fault and locate intermittent wiring faults.
If wiring and bus appear good, check module software/firmware levels for BICM F and related controllers; apply manufacturer updates if available.
If the module is not communicating or continues to send invalid data, consider replacing BICM F after confirming wiring, power, grounds, and software are correct.
After repair or module replacement, clear codes and perform operational checks; road test and re-scan to ensure code does not return.