U0187

Universal

Lost Communication With Digital Disc Player/Changer Module A

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

The vehicle has detected that it cannot communicate with Digital Disc Player/Changer Module A over its communication network. The player or changer may be unavailable, but this code does not by itself prove that the module has failed. The exact equipment and effects depend on the vehicle.

Report an error with this code

⚠️ Before You Begin (Safety First)

This fault is generally related to an entertainment system, but a distraction from troubleshooting or an unexpectedly unavailable display or audio control could affect driving. Do not troubleshoot while driving. Stop safely if an inoperative system distracts you or interferes with another function you rely on.

Common Symptoms

  • There may be no noticeable symptoms if the code is intermittent or the vehicle does not use the affected player or changer.
  • The disc player or changer may be unavailable or fail to respond to controls because other modules cannot communicate with it.
  • An infotainment message or warning may appear, depending on the vehicle.
  • Audio or related controls may behave unpredictably if the communication interruption affects their operation.

Common Causes

  • A temporary network interruption, such as one associated with a low or unstable vehicle supply voltage.
  • Loss of power or ground to the digital disc player/changer module.
  • A loose, damaged, or corroded module connector.
  • Open, shorted, or damaged communication wiring.
  • A fault in the module or another part of the communication network.

Diagnostic Steps

  1. Note whether the player or changer is actually unavailable and record any messages or other symptoms; the code can be present without an obvious problem.
  2. If you have a suitable scan tool, record all stored codes from all accessible modules before clearing anything. Related communication codes can help show whether the issue is isolated or broader.
  3. With the vehicle safely parked, check the owner’s manual for any relevant audio-system fuse and inspect it only if it is safely accessible. Replace a failed fuse only with the specified type and rating; if it fails again, seek diagnosis rather than repeatedly replacing it.
  4. With the vehicle off, visually inspect accessible wiring and connectors for looseness or obvious damage. Do not force access or probe communication circuits without vehicle-specific information.
  5. If the fault returns or the module remains unavailable, have a technician test the module’s power, ground, and network connections before replacing parts.

When to Call a Professional

A technician can scan all modules for related communication codes, check whether Module A responds, and inspect its power, ground, connectors, and network wiring using vehicle-specific service information. If those checks are satisfactory, further module or network diagnosis may be needed before considering replacement.

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Commonly Asked Questions

Does U0187 prove that the disc player/changer module has failed?

No. It reports lost communication with the module. Power, ground, connectors, wiring, network conditions, or a temporary voltage disturbance can also prevent communication.

Can this code appear if the player still seems to work?

Yes. A communication interruption may be intermittent, or the code may be stored even when the system currently appears to work. Related codes and scan results can help clarify the condition.

Should I replace the player or changer right away?

Not based on this code alone. Check the module’s power, ground, connectors, and network communication first, using information specific to the vehicle.

Can I keep driving with U0187?

The code is generally associated with entertainment equipment, but its practical effect varies. Avoid troubleshooting while driving, and stop safely if an unavailable system distracts you or interferes with a function you rely on.

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