U0142

Universal

Lost Communication With Body Control Module B

Definition source: General OBD-II reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The vehicle detected that other control modules could not communicate with Body Control Module B over the vehicle network. A body control module manages body-related electrical functions, but the functions assigned to module B vary by vehicle. Communication loss may affect those functions or cause warning messages; the code alone does not prove the module itself has failed.

Report an error with this code

⚠️ Before You Begin (Safety First)

If lighting, wipers, door locks, or another function needed for safe driving is not working, avoid driving until it is checked. Stop in a safe place if visibility or vehicle security is compromised. Seek qualified help if the issue affects a safety system or the vehicle behaves unpredictably.

Common Symptoms

  • There may be no noticeable symptoms if the communication interruption is brief or the affected functions are not in use.
  • Warning lights or a message may appear if another module detects that it cannot communicate with Body Control Module B.
  • Body-related electrical functions assigned to that module may work intermittently or stop working; the affected functions depend on the vehicle.
  • Other communication codes may appear if the problem involves a shared network circuit or power supply.

Common Causes

  • A loose, damaged, corroded, or poorly connected network wire or connector can interrupt communication.
  • A fuse, power supply, or ground serving the module may be faulty or intermittent.
  • A weak or unstable vehicle battery or charging supply can disrupt module operation or network communication.
  • Network interference or a fault in another connected module or circuit may prevent communication.
  • Body Control Module B may have an internal fault, but this should be established by testing rather than assumed from the code.

Diagnostic Steps

  1. Note any warning messages and body-related functions that are not working or are intermittent; this can help identify what may be affected.
  2. Check the battery terminals for looseness or visible corrosion, and address obvious problems safely. Unstable voltage can affect module communication.
  3. With the vehicle off, visually inspect accessible fuses and connectors identified for the body control system in the owner's information. Do not force connectors or probe wiring.
  4. If the code returns, have the vehicle scanned across all modules and use model-, year-, and engine-specific service information for further electrical checks.

When to Call a Professional

Use a scan tool that can communicate with all vehicle modules. Check for related network or power-supply codes, confirm whether the vehicle uses a separately identified Body Control Module B, and use vehicle-specific service information to test its power, grounds, connectors, and network circuits. Confirm the cause before replacing a module.

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Commonly Asked Questions

Does U0142 prove that Body Control Module B needs replacement?

No. The code reports lost communication, which can result from wiring, connectors, power, grounds, network problems, or a module fault. Testing is needed to identify the cause.

Can this code appear even if the vehicle seems to work normally?

Yes. A brief or intermittent communication loss may leave no obvious symptom, and the affected functions depend on the vehicle's design.

Is Body Control Module B the same component on every vehicle?

Not necessarily. Module naming and the functions assigned to it vary. Vehicle-specific service information is needed to identify the module and its circuits.

Can I keep driving with U0142?

That depends on which functions are affected. Do not drive if required lights, wipers, or other equipment needed for safe operation are not working.

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