U1101 on 2007-2009 Hyundai Entourage — Lost Communication (Manufacturer Specific)
1 vehicles · 1 makes · $200-$700 repair
How to diagnose and fix U1101: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Hyundai Entourage · 2007–2009
The Entourage 3.8L V6 has a high rate of premature alternator failure, commonly caused by the front valve cover gasket leaking oil onto the alternator.
Common Symptoms
- Battery light on dashboard while driving
- Slow engine cranking
- Electrical accessories (radio, lights) dimming
How to Fix
Replace the alternator with a quality remanufactured unit. Check for oil from a leaking valve cover gasket on the alternator and repair the leak, or the replacement alternator can fail too.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Denso 210-0711 remanufactured 130-amp alternatorOEMDenso 210-0711
alternator replacement only after charging-output, ripple and voltage-drop tests confirm alternator failure Fitment/availability: 2007-2008 Hyundai Entourage 3.8L without rear DVD/rear entertainment, 130-amp configuration. Confirm VIN, o…
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Owner tips & cautions
- TipAsk the dealer about a body control module software update — Hyundai released a reflash that fixes the parasitic drain from the sliding door modules
- TipIf the van sits for more than 3 days, disconnect the negative battery terminal or install a battery disconnect switch ($15 from Amazon)
Sources for this issue (2)
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U1101 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U1101 mean?
U1101 stands for "Lost Communication (Manufacturer Specific)." This is a manufacturer-specific network communication code meaning a module has lost communication with another module on the vehicle's data bus (the exact module varies by manufacturer, since U11xx codes are not standardized like generic U-codes). Vehicle modules talk to each other over a shared data network, and this code is logged when expected messages from a particular module stop arriving or the module fails to respond. Depending on which system is affected, you may see warning lights, disabled features, or reduced functionality. It generally indicates a wiring, connector, power/ground, or module problem on the communication network rather than a mechanical fault. Because the meaning is brand-specific, manufacturer service information is needed to identify the exact module involved.
What are the most common causes of U1101?
The most common causes of U1101 are: Damaged, corroded, or loose data bus wiring or connectors, Open or short in the CAN/communication wiring, Lost power or ground to the affected module, Blown fuse feeding a network module, Failed or unresponsive control module, Corrosion or water intrusion at a module connector, Another faulty module disrupting the data bus. The specific cause varies by vehicle.
How much does it cost to fix U1101?
Repair costs for U1101 range from $200 to $700, depending on the vehicle and root cause.
Which vehicles are affected by U1101?
Au7o has documented U1101 across 1 vehicle models from 1 manufacturers: Hyundai.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.