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 shares the same high alternator failure rate as other Lambda V6 Hyundai vehicles. The alternator fails prematurely between 60,000-80,000 miles. Additionally, the Entourage suffers from parasitic battery drain caused by the power sliding door modules not fully entering sleep mode. This drains the battery overnight if the vehicle sits for more than 2-3 days. The combination of alternator weakness and parasitic drain frequently results in dead batteries and stranded owners.
Common Symptoms
- Dead battery after sitting 2-3 days
- Battery light on dashboard while driving
- Slow engine cranking
- Multiple jump starts needed per month
- Electrical accessories (radio, lights) dimming
How to Fix
Replace the alternator with a quality remanufactured unit. For parasitic drain, have a mechanic perform a current draw test with a multimeter to identify the offending circuit. The sliding door control module is the most common culprit — unplugging it overnight as a test confirms this. Hyundai released a software update for the body control module that addresses the sleep mode issue. Disconnect the battery negative terminal if the vehicle will sit for more than 3 days.
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…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
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)
Find U1101 by make
Browse every documented model and issue for your make.
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.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.