U0500

Code

Generic U — Network/User

Invalid Data Received From Control Module

Brand: Generic

Type: U — Network/User

Views: UK: 32 EN: 34 RU: 31

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Damaged or corroded CAN/LIN wiring or connectors
Faulty control module transmitting malformed data
Poor power or ground to one or more modules
Incorrect or mismatched software/firmware in a module
Failed or incorrect termination resistors on the bus
Intermittent wiring short to battery/ground or to another signal

Symptoms

Malfunction indicator lamp (MIL) or communication warning lamp illuminated
One or more modules not responding to a scan tool or showing showtime/no communication
Loss or intermittent loss of functions controlled by the affected module(s) (ABS, ABS, HVAC, instrument cluster, transmission, etc.)
Erratic operation of systems that rely on network data
Multiple communication DTCs present across modules

What to check

Read and record all U-codes and module-specific codes from every control module with a capable scan tool
Check battery voltage and ground quality; verify battery is fully charged and charging system is healthy
Visually inspect all network connectors and harnesses for corrosion, damaged pins, or loose connectors
Check for recent module replacements or software updates and confirm correct calibration/part numbers
Look for aftermarket accessories tied into the data bus and disconnect if present
Perform a wiggle test while monitoring codes/communications to find intermittent connector/wiring faults

Signal parameters

CAN bus recessive voltage ~2.5 V on CAN_H and CAN_L (verify approximate idle voltages with meter/scan tool)
Dominant state voltages: CAN_H ~3.5 V, CAN_L ~1.5 V (look for correct swing on oscilloscope)
CAN differential voltage when active ~1.5–2.5 V peak
Message IDs and expected message frequency (messages per second/Hz) for the suspected network
RX/TX error counters and bus-off status for each module
Checksum/CRC or counter fields in suspect message payloads if available

Diagnostic algorithm

Capture and record all U and related codes from every module; note freeze frame data. 2) Clear codes and attempt to reproduce; if code returns, proceed. 3) Confirm battery voltage and good chassis/engine ground connections. Repair as needed. 4) Visually inspect network connectors and wiring for damage/corrosion; repair any issues. 5) Verify presence and correct part number/software level of recently replaced modules; reflash to factory calibration if required. 6) Use a scan tool to confirm each expected module is present on the bus and responding; note any missing nodes. 7) Monitor live network traffic (bus load and message IDs) or capture with an oscilloscope/logic analyzer. Look for malformed frames, excessive error frames, or long dominant states. 8) Check termination resistance across CAN_H and CAN_L at multiple locations; replace/repair missing or incorrect termination resistors. 9) Isolate the fault by disconnecting suspect modules or aftermarket devices one at a time while observing bus health. 10) If a module is identified as the source (corrupted messages, bus-off events tied to a node), confirm power/ground and replace or reprogram the module per manufacturer procedures. 11) After repair, clear codes, verify normal network traffic and confirm no recurrence under road/test conditions.

Likely causes

Faulty module sending corrupted messages
Poor/loose connector or pin corrosion on a network node
Battery/charging system low voltage or missing ground at the affected module
Incorrect software calibration or incomplete reflash after module replacement
Broken or shorted CAN bus wiring or missing termination

Fault status

⚠️ Status

A control module reported receiving invalid or corrupted data from another module on the vehicle communication network; communication integrity error detected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.5 hours