Code
U0446
HYUNDAI
U — Network/User
Invalid Data Received From Body Control Module “E”
Views:
UK: 13
EN: 23
RU: 22
AI status
Completed
Completed
100%
Causes
- Faulty Body Control Module (BCM)
- Intermittent or open/short in CAN high/low wiring to BCM
- Poor ground or supply voltage to BCM
- Corroded or loose BCM connectors
- Incorrect or corrupted BCM programming/software
- Aftermarket electronics interfering with the CAN bus
Symptoms
- Instrument cluster or dash may display a communication or network warning
- Loss or erratic operation of body functions (locks, interior lights, wipers, keyless entry)
- Intermittent starts or accessory functions not operating
- Multiple related U-codes present on scan tool
- No obvious mechanical fault with affected body systems
What to check
- Connect a scan tool and record all U and B codes, freeze frame, and current BCM data
- Check battery voltage (should be stable ~12.6V with key off, ~13.5–14.5V with engine running)
- Inspect BCM connector(s) for corrosion, bent pins, water intrusion or damage
- Visually inspect CAN wiring harness for chafe, repairs, or aftermarket taps
- Verify good ground and power supply to BCM (measure continuity to chassis and battery)
- Check for termination resistor across CAN_H and CAN_L (~60 ohms total) at key points
Signal parameters
- CAN bus differential voltages: idle (recessive) ~2.5V on CAN_H and CAN_L; dominant state produces ~1.5V on CAN_L and ~3.5V on CAN_H
- Typical CAN bus bitrate for body networks commonly 500 kbps (verify vehicle-specific spec)
- Expected bus termination ~60 ohms total across CAN_H and CAN_L (two 120-ohm terminators in parallel)
- BCM sends periodic messages (door/lock/ignition status) at fixed intervals — corrupted or missing frames indicate a fault
- Look for abnormal voltage spikes, excessive noise, or missing dominant/recessive transitions on the scope
Diagnostic algorithm
- Read and record all stored codes and live data from all modules. Note any related U-codes.
- Verify battery and charging system voltages. Recharge or replace battery if voltage is low or unstable.
- Inspect BCM connector and surrounding area for moisture, corrosion, or damage. Repair or replace connector as needed.
- With key on, backprobe CAN_H and CAN_L at the BCM and at a nearby module. Use an oscilloscope or a CAN bus tester to check for proper differential waveforms and message traffic.
- Check continuity and resistance of CAN twisted pair between BCM and other network nodes. Look for shorts to chassis or power.
- Verify proper ground(s) for BCM (continuity to chassis and battery negative). Clean and tighten ground connections.
- Disconnect any recently installed aftermarket modules or accessories and retest.
- If wiring and power/ground check good but invalid data persists, check BCM software/flash level against manufacturer specifications and apply updates or reflash per service procedure.
- If reprogramming does not clear the fault and all tests show correct wiring and voltages, consider BCM replacement following OEM pairing/coding procedures.
- After repairs, clear codes and perform a road test or operational checks to confirm the fault does not reoccur.
Likely causes
- Water ingress or corrosion at BCM connector causing bad signal levels
- Damaged CAN twisted pair (chafed, pinched, or shorted to chassis)
- Weak battery or poor battery terminal connection causing data corruption
- BCM internal failure (memory or processor error)
- Recent module replacement not coded/programmed to the vehicle
Fault status
Status
Invalid data received from Body Control Module E — communication frames from BCM 'E' are corrupted or out of specification.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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