U0140: Lost Communication With Body Control Module
A generic network and communication trouble code, same meaning on every brand.
Unpredictable - the body computer touches everything from lights to fuel pump relays. Minimal driving.
Symptoms
- Gauges dead or erratic
- Lights, wipers, locks misbehaving together
- No-start in some designs
Likely causes, most common first
- Body control module power or ground
- CAN wiring faults
- Water intrusion into the BCM (common under-dash location)
Read U0140 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
U0140 means the body control module went silent on the network. Because the BCM arbitrates so many small systems, its loss looks like electrical chaos rather than one clean failure.
Check the module's location against your car's water history - windshield leaks dripping onto under-dash modules write this story often. Diagnosis first; the module is the last suspect, not the first.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning U0140
“Due to the loss of power steering the tech at Rainier Dodge of Olympia performed electrical testing per diagnostic chart and found water intrusion into steering harness that has corroded wiring from the body harness into electric steering gear motor/module unit. The electric power steering gear assembly and harnesses must be replaced. The vehicle recieved a fault code U0140 stating loss of communication with body control module.”2023 Ram Promaster · Jul 2026
“The contact owns a 2022 Jeep Grand Cherokee L. While driving approximately 40 MPH, the air bag, ABS, parking brake, check engine, seat belt, and collision warning lights illuminated. Additionally, the messages "START/STOP not ready," "ACC Disabled", "Cruise Control", "Service Air Bags System", "Blind Spot Alert Off", and "Service ESC" were displayed. The vehicle was taken to an auto parts store, where a handheld diagnostic machine retrieved DTC: U0140. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 73,945.”2022 Jeep Grand Cherokee L · Apr 2026 · 73,945 mi
“Coolant leaking into engine. Check engine light on. Codes p0302, p0316, u0140. I was told by the ford dealership that ran codes that the only correction for the issue is a full long block replacement.”2018 Ford Escape · Aug 2025
Show 6 more owner reports
“The problems listed in my vehicle are the following - U0073: Control Module Communication Bus A Off - U0100: Lost Communication With Engine Control Module - U0121: Lost Communication with Electronic Brake Control Module - U0140: Lost Communication With Body Control Module - P0700: Transmission Control Module Requested MIL Illumination I believe this is due to a bad design in the wiring. Also the electric brake vacuum broke which is a common problem.”2020 Chevrolet Malibu · Jul 2024
“Car went crazy one day while behind the wheel everything malfunctioned then car shut off and won't start again. I could of easily got into an accident had there been any other vehicles around. Kids were scared. Codes come up as U0100,U0140,U0101,C0242,B0081-0F,B0081-71,B1370-01,B1370-06,U0155-00,U0170-00,P0856-00.”2008 Cadillac CTS · Jul 2023
“I keep having problems with my 2018 jeep wrangler and my check engine light came on then went away so today 30jan2021 I checked my system with a obd scanner and it popped up the code u0140 lost communication with the body control module.”2018 Jeep Wrangler · Jan 2021
“When a passenger gets in the pasenger seat the air bag and no seatbelt comes on blinking and dinging the whole time I am driving. Today my check engine light came on so I took it to auto zone and had the codes read adn it came up with the following p0520 engine oil pressure sensor/switch circuit and code u0140 lost communication with body control module.”2013 Dodge Dart · Nov 2019 · 2,000 mi
“After a weekend of camping (rv) my avalanche would not start, battery less than one year old. The rpm $ mph were moving up & down, clicking sounds were coming from the front seat arm rests, no power to the windows & locks. Vehicle was parked & both the avalanche & rv had to be towed. Diagnose-u0140 loss of communication of bcm, defective body control module, replaced control module.”2007 Chevrolet Avalanche 1500 · Oct 2016 · 71,028 mi
“Driving down the highway @ 55mph and the power steering cuts off, the power brakes cut off, the ABS light comes on, the turn signals start going on and off at random, the gauges jump up and down nonstop. I just picked up my car and was told it referenced tsb#08-07-30-021 (NHTSA#10025402). The check engine light is still on because of this problem. The shop referenced the following error codes from the check engine light: p0575 u7300 u0121 u0140 thank goodness no one was behind me or around me at the time because I was unable to properly steer the vehicle, brake, or accelerate. This is a major problem that should be addressed by gm. *tr”2007 Chevrolet Cobalt · Jul 2014 · 77,653 mi
Cars that report U0140 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with U0140?
Unpredictable - the body computer touches everything from lights to fuel pump relays. Minimal driving.
How much does it cost to fix U0140?
Typical US repair costs range from $120 for the simplest fix (power/ground and network diagnosis) to $1,500 in the worst case. The right number depends on which cause your car has - see the causes list.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.