U04AD

Code

Generic U — Network/User

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

Brand: Generic

Type: U — Network/User

Views: UK: 24 EN: 27 RU: 26

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty or intermittent CAN/LIN wiring between battery interface module and vehicle networks
Corroded, loose or damaged connectors/pins at battery interface or gateway modules
Battery Interface Control Module (BICM) internal fault or software corruption
Incorrect or mismatched software/calibration between modules
CAN bus termination, wiring short to battery or ground, or high bus error rate
Low supply voltage or poor ground to the battery interface module

Symptoms

Malfunction indicator lamp (MIL) or EV/HV system warning illuminated
Reduced power, limited drive or limp-home mode for hybrid/EV system
Charging disabled or charging faults reported
Loss of regenerative braking or reduced regen performance
Battery pack status, SOC or SOH readouts missing/invalid on instrument cluster
Intermittent or persistent communication-related faults in scan tool data

What to check

Read all stored and pending U-codes and freeze-frame data with a capable OEM-level scan tool
Confirm presence and frequency of battery interface messages on the vehicle network (CAN/LIN) using a diagnostic tool or oscilloscope
Visually inspect connectors and wiring at the battery interface module, gateway, and related junctions for damage, corrosion, or moisture
Measure module supply voltage and grounds at the battery interface connector (compare to spec)
Check CAN bus differential voltages and termination resistance (approx. 60 ohms across CANH–CANL) with ignition in specified state
Look for related codes (bus-off, controller lost communication, checksum or counter errors) that narrow root cause

Signal parameters

Message ID: OEM-specific (hex) — verify expected ID for Battery Interface Control Module M
Data Length Code (DLC): commonly 8 bytes — check for unexpected DLC value
Message frequency: expected periodic interval (e.g., 1–100 Hz depending on signal); check for missing or irregular timing
Payload fields: pack voltage, pack current, SOC, SOH, cell min/max, temperatures — verify values within known physical ranges
Checksum/CRC: verify checksum field matches calculated checksum for the message
Rolling counter: verify incrementing counter to detect dropped/duplicated frames

Diagnostic algorithm

Retrieve all codes and freeze-frame data; note time stamps and related events. Do not clear codes yet.
Record live data for battery pack signals and message timing via an OEM scan tool. Confirm which signals are invalid, out-of-range or missing.
Inspect exterior connectors and harnesses for damage, corrosion, or moisture. Repair or replace damaged wiring/connectors.
With ignition in diagnostic state, measure CANH/CANL idle voltages and the total termination resistance across the bus. Look for shorts or open circuits.
Use a scope or CAN bus diagnostic tool to capture frames from the Battery Interface Control Module M. Check message ID, DLC, frequency, checksum and rolling counter integrity.
Verify module supply voltage and ground at the battery interface connector while attempting communication. Repair poor power/ground connections.
If wiring and power/grounds are good, attempt to reinitialize or reflash module software per OEM procedures. Confirm software compatibility between modules.
If fault persists after wiring and software checks, consider replacing the Battery Interface Control Module M or gateway module following OEM replacement and programming procedures.
After repairs, clear codes and perform a functional test and road test (or required charging/discharging procedure) to confirm message stability and absence of recurrence.

Likely causes

Damaged CAN harness or connector to the battery interface module
Corroded pins causing intermittent contact and invalid frames
Faulty battery interface module producing corrupted messages (bad checksum/counter)
Bus termination missing or incorrect causing reflections and corrupted data
Module low supply or ground problem causing unstable transmissions

Fault status

⚠️ Status

Invalid or corrupted data received from Hybrid/EV Battery Interface Control Module M — messages failed checksum/counter/format validation or contained out-of-range values.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-4.0 hours