OBD-II trouble code
U0142: Lost Communication with Body Control Module C
A module on the network can no longer hear from body control module C, an additional body controller on feature-rich vehicles. Usually a power, ground, or wiring fault, it can disrupt the body electronics that controller manages.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $110 – $1,100
- DIY difficulty
- Advanced DIY
What does U0142 mean?
U0142 is stored when another module on the vehicle's communication network stops receiving messages from body control module C. Feature-rich vehicles often split body-electronics duties across more than one body control module (A, B, C, and beyond); 'C' is an additional controller that handles a portion of the body functions — things like lighting, door and access features, comfort and convenience systems, or interior electronics, depending on the vehicle. When the network can no longer reach it, U0142 records that this controller has gone silent.
The causes are the familiar lost-communication faults rather than a problem with any single accessory. The module may have lost power or ground through a blown fuse, corroded ground, or failed relay. The communication wiring or a connector at the module can be damaged, chafed, or corroded — connectors behind trim, under the dash, or in the doors are common trouble spots. The module's internal communication circuitry can fail, or another module on the bus can disrupt the network. Low 12-volt system voltage, a draining battery, or a recent battery disconnect can also trigger it.
What you notice depends on which functions this controller owns. Features it manages may stop working, behave erratically, or warn, and the check engine or a body-system warning light may appear. Core driving usually continues, so the vehicle generally remains driveable, but affected convenience or safety-related body features may be unavailable until the fault is repaired. Because the exact function split is vehicle-specific, identify what body control module C controls on your vehicle before chasing individual symptoms.
Common causes
- Blown power or ground fuse for body control module C
- Corroded or loose ground at the module
- Damaged or chafed communication wiring to the module
- Corroded or backed-out terminals at a connector behind trim, under the dash, or in a door
- Failed internal communication circuitry in the module
- Another module on the bus disrupting network communication
- Low 12-volt system voltage or a recent battery disconnect
- Water intrusion or corrosion at the module or its harness
Symptoms
- Check engine light or a body-system warning light on
- Body features handled by this controller stop working or behave erratically
- Lighting, door/access, or convenience features may be affected
- Intermittent operation of affected accessories
- Scan tool can't communicate with body control module C
- Symptoms may appear after a battery disconnect or jump start
- Symptoms may be intermittent with a marginal connection
Diagnostic steps
- 1.Identify which functions body control module C handles on the specific vehicle.
- 2.Scan all modules; confirm body control module C is unreachable while others respond.
- 3.Check the module's power and ground fuses and relays.
- 4.Inspect the ground points and communication connector at the module for corrosion, looseness, and damage.
- 5.Inspect the communication wiring along its routing for chafing and damage.
- 6.Measure the communication bus lines at the module connector and verify continuity back to the bus.
- 7.Test the 12-volt battery and charging, since low voltage can cause intermittent communication loss.
- 8.If power, ground, and wiring are good but the module still won't communicate, suspect an internal module fault requiring replacement and programming.
Repair cost
$110 – $1,100
A blown fuse, corroded ground, or connector repair is the cheapest fix at $110-$400 once located. Wiring repair runs $200-$600. Diagnostic time often adds $100-$200. Replacing and programming a body control module is the most expensive outcome at $500-$1,100 or more, and is a last resort after wiring, power, and ground are ruled out.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with module communication / can bus diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.