U0149

Universal

Lost Communication With Gateway D

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’s control modules are not receiving expected messages from Gateway D. A gateway routes information between vehicle networks, so this fault may affect communication between systems rather than identify a failed part. Some functions or warning indicators may be affected, though the code can also be present without noticeable symptoms.

Report an error with this code

⚠️ Before You Begin (Safety First)

If braking, steering, or other safety-related functions behave abnormally, or a safety warning remains on, stop driving when it is safe to do so and arrange for the vehicle to be checked. If the vehicle drives and behaves normally, have the communication fault diagnosed promptly; do not bypass safety systems.

Common Symptoms

  • Warning lights or communication messages may appear if other modules lose information routed through Gateway D.
  • Some vehicle features may become unavailable or behave inconsistently when their modules cannot exchange required messages.
  • Other communication-related codes may be stored in multiple modules.
  • The fault may be intermittent if a connection, power supply, ground, or network signal is inconsistent.
  • There may be no noticeable symptoms if the communication interruption is temporary or does not affect a function the driver uses.

Common Causes

  • Gateway D may have an interrupted power supply or poor ground, preventing it from operating or communicating reliably.
  • A loose, damaged, corroded, or poorly connected wiring connector may interrupt the gateway’s power, ground, or network connection.
  • A fault elsewhere on a vehicle communication network may prevent messages from reaching or leaving the gateway.
  • Low or unstable vehicle voltage may disrupt communication among control modules.
  • Gateway D may have an internal fault, but the code alone does not establish that the gateway needs replacement.
  • A software, configuration, or communication issue involving the gateway or another module may contribute to the fault.

Diagnostic Steps

  1. Note any warning lights, feature problems, or circumstances when the code appears; this information can help distinguish an intermittent communication issue from a persistent one.
  2. Check the battery terminals and visible battery cables for looseness or corrosion. Poor electrical connections can affect module communication.
  3. With the vehicle off, inspect accessible wiring and connectors for obvious damage, moisture, or loose connections. Do not unplug modules or probe connectors unless the vehicle-specific service information says it is safe.
  4. Check relevant fuses using the owner’s manual or vehicle-specific fuse information. Replace a blown fuse only with the specified type and rating; if it blows again, seek diagnosis rather than repeatedly replacing it.
  5. Use a compatible scan tool, if available, to record codes from all accessible modules before clearing anything. Multiple communication codes can help identify whether the issue involves one module or a wider network problem.
  6. If the code returns or warning lights or functions are affected, arrange professional diagnosis. Network testing and gateway checks require vehicle-specific information and suitable equipment.

When to Call a Professional

Have a technician scan all accessible modules and compare their communication status and stored codes. Check battery and charging-system condition, then verify Gateway D’s power, ground, connectors, and network wiring using vehicle-specific service information. A communication-network fault or another module can cause this code, so confirm the fault before replacing the gateway. Software updates or configuration checks may be relevant depending on the vehicle.

Compare component listings

Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.

Search Amazon Search eBay

Commonly Asked Questions

Does U0149 prove Gateway D has failed?

No. It records lost communication with Gateway D, but a power, ground, wiring, connector, network, voltage, or software issue can also interrupt communication.

Can I drive with this code?

It depends on which functions are affected. If the vehicle behaves normally, arrange diagnosis promptly. Stop driving when safe and seek assistance if braking, steering, or another safety-related function is abnormal.

Why might there be no symptoms?

A communication interruption can be temporary, or it may affect messages that do not produce a noticeable change in everyday driving. The code may still warrant investigation, especially if it returns.

Why should all modules be scanned?

Other modules may store related communication codes that help show whether the fault is limited to Gateway D or affects a wider part of the vehicle network.

Should I replace Gateway D based on this code?

Not without diagnosis. A technician should first check relevant power, ground, connectors, network communication, and vehicle-specific software or configuration requirements.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.