U0157 Code Symptoms, Causes, Diagnosis & Complete Repair Guide

When the vehicle’s information‑center warning lamp flashes or remains illuminated, you may notice interior illumination flickering, courtesy lights that never turn on, and power‑window or door‑lock buttons that feel unresponsive. These symptoms appear suddenly and can worsen as the vehicle ages, because the body‑control network relies on continuous data exchange with Information Center B. Early identification prevents loss of convenience functions and avoids cascading faults in other body‑control modules.

Symptoms

• Intermittent or dead interior lighting – dome light, map lights, and footwell LEDs fail to activate.
• Non‑responsive power‑window or power‑door‑lock switches – pressing the button produces no movement or click.
• Flashing or steady information‑center warning lamp on the instrument cluster.
• Loss of courtesy‑light activation when doors are opened, often accompanied by a “no‑light” message on the dash.

These cues point directly to a breakdown in the communication path between the vehicle’s CAN network and the Information Center B module.

Why Information Center B Problems Occur

Communication Network Failure

The CAN (Controller Area Network) bus links all body‑control modules. A disruption—such as a corrupted bus frame or a timing‑error caused by a malfunctioning gateway—prevents the Engine Control Module, Body Control Module, and Information Center B from exchanging data. When the network drops packets, the Information Center B cannot confirm status updates, triggering U0157.

Faulty Information Center B Module

Internal circuit‑board damage, moisture intrusion, or component fatigue can render the module unable to transmit or receive messages. Even if the wiring is intact, a defective microcontroller inside the module will cause a persistent loss of communication.

Wiring or Connector Issues

Corroded pins, broken harness wires, or loose connector clips break the physical link to the module. A single high‑resistance joint can corrupt CAN‑high/low voltage levels, causing the control unit to time out and set U0157.

Power‑Supply Problems

Information Center B draws power from the vehicle’s 12 V system through a fused supply. A marginal fuse, deteriorated power relay, or voltage drop below 9 V under load can starve the module, leading to intermittent shutdowns and communication loss.

Software Corruption

Factory‑installed firmware may become corrupted after an incomplete flash, a battery disconnect, or a failed reprogramming attempt. Errant code can disable the module’s CAN interface, prompting the diagnostic trouble code.

Diagnostic and Repair Procedures

1. Scan the CAN bus – Use a professional OBD‑II scanner capable of reading body‑control codes. Confirm U0157 and note any additional network‑related codes (e.g., U0100, U0140).
2. Verify power supply – Measure voltage at the Information Center B fuse location with the ignition on. Voltage should be 12.4‑12.8 V. Replace a blown or weak fuse (typically 5 A–10 A).
3. Inspect wiring harness – Follow the harness from the main body‑control junction to the Information Center B. Look for cracked insulation, chafed wires, and corrosion. Perform a continuity test on each pin; resistance above 0.5 Ω indicates a problem.
4. Check connectors – Disconnect and reconnect the module’s plug. Clean pins with electrical contact cleaner and ensure a firm latch.
5. Perform a module‑communication test – Many scan tools can request a “read data by identifier” from Information Center B. A successful response confirms functional communication. Failure after wiring verification points to a defective module.
6. Reprogram the module – If the software version is outdated or corrupted, download the latest factory firmware and flash the module using the manufacturer’s programming tool. Verify successful flash by re‑scanning for codes.
7. Replace the module – When communication tests repeatedly fail despite clean wiring and proper power, install a replacement Information Center B. Ensure the new unit is VIN‑matched and pre‑programmed to the vehicle’s configuration.

Typical labor for a full diagnosis and reprogramming ranges from $150‑$250. Module replacement, including programming, averages $600‑$900 for the part plus $200‑$300 labor.

When Information Center B Replacement Makes More Sense Than Repair

If the module fails the communication test after exhaustive wiring and power‑supply checks, internal damage is the most likely cause. While board‑level repairs can temporarily restore operation, moisture‑induced corrosion or cracked traces often recur, leading to repeated failures. A fresh, factory‑specification unit eliminates the risk of hidden defects and restores full body‑control functionality.

Modern control modules are complex and integrated with security and immobilizer systems. That’s why choosing a replacement isn’t only about the hardware—it’s about correct programming and compatibility. Flagship One specializes in VIN‑matched control modules, providing a plug‑and‑drive solution backed by warranty. Their modules arrive pre‑programmed to the exact software version required for your vehicle, ensuring seamless integration with the CAN network and eliminating dealer‑programming delays.

Preventive Maintenance

• Regularly inspect wiring harnesses for signs of wear, especially in areas subject to movement (door jambs, seat rails).
• Keep connectors clean and dry; apply dielectric grease to prevent corrosion.
• Maintain battery health; a weak battery can cause voltage drops that stress body‑control modules.
• Schedule periodic CAN‑bus scans during routine service visits to catch emerging communication errors before they trigger a fault.
• Avoid aftermarket modifications to interior lighting or accessory circuits that bypass the Information Center B, as they can introduce voltage spikes or ground loops.