Code
U2105
HUMMER
U — Network/User
Invalid data received from another control module
AI status
Completed
Completed
100%
Causes
- Faulty sending control module (bad sensors, corrupted outputs, or internal fault)
- Software/firmware mismatch after updates or incorrect calibration
- Corroded/damaged wiring, pins, or connectors on the network bus or module harness
- Intermittent or low battery/poor ground causing corrupted messages
- Faulty bus termination or missing termination resistor(s)
- Electromagnetic interference (EMI) or short to power/ground on bus lines
Symptoms
- MIL or dash warning(s) related to affected systems (may or may not illuminate)
- Loss or intermittent operation of features controlled by the offending module (e.g., instrument cluster, ABS, body functions)
- Erratic or unexpected behavior from one or more systems
- Multiple communication-related DTCs present
- Possible no-crank/no-start if powertrain module data is affected
What to check
- Retrieve all stored and pending DTCs and note module reporting U2105 and any related codes
- Check freeze-frame and event data for voltage, bus status, and time of failure
- Verify vehicle battery voltage and ground connections (measure at terminals and near modules)
- Visually inspect all related connectors, pins, and harnesses for corrosion, damage, or loose pins
- Check for recent software updates or module replacements and record calibration/part numbers
- Use a scan tool to view live data from the suspected sending module and compare to other modules
Signal parameters
- High-speed CAN typical idle voltages: CANH ≈ 2.5 V ±0.5 V, CANL ≈ 2.5 V ±0.5 V
- CAN dominant state typical voltages: CANH ≈ 3.5 V ±0.5 V, CANL ≈ 1.5 V ±0.5 V (differential ≈ 2.0 V ±0.5 V)
- Termination resistance: ~60 Ω across CANH-CANL (two 120 Ω terminators in parallel)
- LIN idle (recessive) ≈ vehicle battery voltage (≈11–14 V); dominant ≈ ~0 V
- Common CAN bus data rates: 250 kbps or 500 kbps (confirm vehicle-specific)
- Expect low bus error frame count during normal operation; repeating errors indicate bus or node fault
Diagnostic algorithm
- Connect a capable OEM-level scan tool and record all U-codes and related DTCs from all modules; note which module reported U2105.
- Check battery state-of-charge and verify good chassis/engine ground connections; repair any battery/ground issues and re-test.
- Review recent service history for module replacements or software updates; confirm software/calibration levels are correct for all network modules.
- Visually inspect connectors and wiring for the reporting module and along the bus for damage, corrosion, or exposed conductors; repair as needed.
- Clear the DTC(s), operate vehicle under conditions that reproduce the fault, and see if U2105 returns to capture freeze-frame data.
- Use a lab scope or CAN/LIN analyzer to capture bus traffic during fault occurrence; look for malformed messages, repeated error frames, or a single node flooding the bus.
- Measure CANH/CANL voltages and differential with key on/run to confirm proper idle and dominant voltages; measure termination resistance across the bus.
- If a suspect sending module is identified, isolate it by disconnecting the module (if safe) and observe whether the DTC returns; swapping with a known-good module or reflashing firmware may be required.
- If hardware and wiring check out, perform recommended reprogramming or software updates on affected modules per manufacturer procedures.
- If fault persists after diagnostics, refer to manufacturer technical bulletins or escalate to dealer/technical support for gateway or module-level repair.
Likely causes
- Specific sending module producing invalid CAN/LIN frames due to internal hardware or firmware fault
- Recent module replacement or update left incompatible software levels
- Damaged CAN/LIN wiring or connector at module-to-bus interface
- Loose or corroded ground or battery connection causing voltage dips and message corruption
- Failed CAN transceiver or gateway within a module
Fault status
Status
Invalid data received from another control module — network message contained corrupted or unexpected data.
Repair difficulty: Medium
Diagnostic time: 1-4 hours
Similar codes
Repair manuals
Manual library for HUMMER
138
Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
-
HUMMER: 2009
-
HUMMER: 2008
-
HUMMER: 2007
-
HUMMER: 2005
-
HUMMER: 2004
-
HUMMER: 2000
-
HUMMER: 1999
-
HUMMER: 1994
-
HUMMER: 1993
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email