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Home / DTC / U044B — Invalid Data Received From Battery Energy Control Module C

U044B — Invalid Data Received From Battery Energy Control Module C

Detailed page for trouble code U044B.

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U044B

Generic U — Network/User

Invalid Data Received From Battery Energy Control Module C

Brand: Generic
Type: U — Network/User
Views: UK: 18 EN: 30 RU: 20
AI status
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Page language: EN

Causes

  • Battery Energy Control Module C is not responding or is sending corrupted CAN messages
  • Open, shorted or intermittent wiring between the battery module and vehicle data bus
  • Faulty or loose connector at the battery energy control module or junctions
  • Loss of power or ground to Battery Energy Control Module C
  • CAN bus/communication network fault (termination, short to battery or ground, high resistance)
  • Software/configuration mismatch after update or module replacement

Symptoms

  • Malfunction Indicator Lamp (MIL) or warning lights related to battery/HV system illuminated
  • Battery pack information (SOC, voltage, current) missing or incorrect on cluster
  • Reduced vehicle performance or limp-home mode related to HV battery control
  • Multiple modules logging related communication or invalid-data DTCs
  • Charging or regenerative braking faults or disabled charging

What to check

  • Read all stored and pending DTCs and freeze-frame data from all modules (scan tool)
  • Check for other communication/network DTCs (U0100, U0073, etc.) to identify bus-wide issues
  • Confirm presence and rate of Battery Energy Control Module C CAN messages with a capable scan tool or oscilloscope
  • Inspect battery module connectors, harness, and intrusion points for corrosion, damage, or water
  • Verify module supply and ground voltages with battery disconnected per HV safety procedures
  • Measure CAN bus voltage levels, bus idle voltages, and check termination resistors if needed

Signal parameters

  • CAN message ID(s) published by Battery Energy Control Module C (module-specific IDs)
  • Message frequency / period (messages per second or ms interval)
  • Alive/counter bytes and checksum/CRC fields if used
  • Pack-level parameters present in messages: pack voltage, pack current, SOC, HV contactor state
  • Cell voltage/min-max values and pack temperature fields (if present)
  • Message payload ranges and expected byte values per manufacturer documentation

Diagnostic algorithm

  1. Safety first: follow HV system isolation and PPE procedures before accessing battery or HV connectors.
  2. Use a scan tool to record U044B and any accompanying DTCs, freeze frame, and which modules reported the fault.
  3. Observe live data and capture CAN traffic while the vehicle is in the state where the fault sets (key on, drive, charging). Note missing or malformed battery module messages.
  4. If messages are absent or corrupted, inspect and secure connectors at Battery Energy Control Module C and intermediate junctions; look for bent pins, corrosion, or water intrusion.
  5. Verify supply voltage and ground at the battery control module (per manufacturer service manual). Repair any low/high supply or poor ground connections.
  6. Check CAN bus integrity: measure bus idle voltages, check for shorts to battery/ground, and verify termination resistors. Repair wiring as needed.
  7. If wiring and power are good but communications remain invalid, verify software/firmware levels and reflash or update per OEM procedure if a mismatch or known bug exists.
  8. If the module does not respond correctly after wiring/power/software verification, replace Battery Energy Control Module C per service instructions.
  9. Clear DTCs, then perform a functional test and road test to confirm fault does not return. Re-scan all modules to ensure no new related codes.

Likely causes

  • Intermittent connector or wiring fault at the battery module harness
  • Battery Energy Control Module C has lost supply or ground
  • CAN bus wiring/termination fault affecting message integrity
  • Module software fault or corrupted calibration after update
  • Module internal hardware failure

Fault status

⚠️ Status
Invalid data received from Battery Energy Control Module C — communication messages missing, corrupted, or out-of-range. Possible communication bus, power/ground, connector, or module fault.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1 - 3 hours

Similar codes

U0401 U0100 U0140 U0442 U0073
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