U0447

Code

Generic U — Network/User

Invalid Data Received From Serial Data Gateway Module A

Brand: Generic

Type: U — Network/User

Views: UK: 38 EN: 177 RU: 58

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty Serial Data Gateway Module A (hardware or firmware)
Open, short or high-resistance wiring on CAN/serial network (including connectors)
Poor power or ground to the gateway or other network nodes
Missing or corrupted message IDs or data (software mismatch or module configured incorrectly)
Bus termination incorrect or missing (improper 120Ω resistors / 60Ω total)
Intermittent connection (corrosion, water intrusion, damaged pins)

Symptoms

Malfunction Indicator Lamp (MIL) or amber/network warning illuminated
Loss or intermittent operation of features that rely on gateway messages (instrument cluster, HVAC, telematics, ABS, traction control, door locks)
Erratic or frozen gauges, blank displays, or wrong instrument readings
Multiple network communication DTCs present
No-crank or no-start if engine control messages are blocked

What to check

Read all stored and pending U-codes and related freeze-frame data with a capable scan tool
Check for other modules reporting communication faults (scan tool network/module list)
Verify battery voltage and charge status (while cranking and at idle)
Visually inspect gateway connectors and harness for corrosion, damaged pins, water intrusion, or repair patches
Verify power and ground at the gateway pin terminals (power present with key on, good ground continuity to chassis)
Measure CAN bus voltages at the gateway: CAN_H and CAN_L resting voltages and differential voltage

Signal parameters

Nominal CAN idle voltages: CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (each), differential ≈ 0 V at idle; when active differential ≈ ±2 V
Typical CAN differential peak ≈ 2.0 V (depending on vehicle network), baud rates commonly 250 kbps or 500 kbps (verify OEM)
Termination: two 120 Ω resistors in parallel ≈ 60 Ω across CAN_H and CAN_L
Expected battery voltage during tests: 11–16 V (engine off/cranking/charging conditions vary)
Ground resistance: chassis ground to module

Diagnostic algorithm

Retrieve and record all U-codes and related active/inactive events with a capable scan tool. Note freeze frame and affected modules.
Check vehicle battery state and verify stable supply voltage. Recharge or replace if low. Re-check codes after stable power.
Inspect connector(s) and wiring to Serial Data Gateway Module A for corrosion, loose pins, water intrusion, or damage. Repair or clean as required.
Verify power and ground at the gateway connector with key on; repair any open/fused feeds or poor ground connections.
With ignition on, use a scan tool to confirm the gateway module and other network nodes appear on the bus. Identify missing nodes.
Measure CAN_H and CAN_L voltages at the gateway and another known-good node. Confirm termination resistance ≈60 Ω. Look for shorts to battery/ground.

Likely causes

Loose/dirty connector or poor ground at the gateway
CAN high/low short to power or ground at or near the gateway
Missing supply voltage to the gateway (fused ignition or battery feed)
Network termination missing or damaged
Gateway software version incompatible after module replacement or update

Fault status

⚠️ Status

Invalid data received from Serial Data Gateway Module A — network messages are corrupted, missing, or unexpected; communication fault logged and MIL may be illuminated.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours