HomeTrouble CodesU0514

U0514 — Invalid Data Received From Mirror Control Module

Generic OBD-II · all makesNetwork / communication

U0514 indicates that a control module on the vehicle communication network has received data from the Mirror Control Module that it cannot validate or recognize. This is a network-integrity fault rather than a mechanical sensor failure, usually pointing to a problem within the mirror module itself, its wiring, or the data bus. Common results include stored warning messages and loss or erratic behavior of mirror-related functions.

Symptoms

What causes it — most likely first

1. Faulty mirror control module

The mirror control module may generate corrupted or incomplete messages due to an internal circuit failure, causing other modules to reject its data as invalid.

2. Wiring or connector fault

A break, short-to-power, short-to-ground, or high-resistance connection in the power, ground, or communication lines can distort the data signal between the mirror module and the network.

3. Corrosion or moisture intrusion

Water entry into the mirror housing, door harness, or connector can create resistance changes or short circuits that interfere with normal module communication.

4. Abnormal system voltage

Low battery voltage, a weak alternator, or poor grounds can cause network voltage fluctuations that lead modules to transmit garbled or incomplete data packets.

5. Aftermarket electrical interference

Non-factory alarms, remote starters, or other devices tapped into the mirror or door harness can inject electrical noise or alter bus signals.

6. Receiving module software fault

In rare cases, the module receiving the mirror data may misinterpret valid information due to outdated software or an internal fault, though this is uncommon.

How it's diagnosed

  1. Record all stored diagnostic trouble codes and freeze frame data, noting any additional U-code communication faults.
  2. Visually inspect the wiring harness and connectors at the mirror control module and mirror assemblies for damage, corrosion, bent pins, or moisture intrusion.
  3. Test battery state of charge and charging system output; verify that the mirror control module has reliable power and ground.
  4. Check communication bus voltage and resistance at the mirror control module connector to identify opens, shorts, or excessive resistance.
  5. If wiring and bus tests pass, evaluate the mirror control module by performing manufacturer-specific self-tests or by substituting a known-good unit.
  6. Consult technical service bulletins for known software concerns; reprogram or update the affected module only if directed by factory information.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to drive with U0514?

Yes. This is a communication fault between control modules and does not typically affect engine operation, braking, or steering. Mirror functions may be limited or unavailable.

Do I need to replace the entire mirror assembly?

Not necessarily. The problem often involves the separate control module, wiring, or connectors. Diagnosis should isolate the failure before replacing the mirror assembly.

Should I replace the PCM or ECM to fix this code?

No. U0514 indicates invalid data originating from the mirror control module, so the cause is almost never the engine computer. Repair efforts should focus on the mirror module, its circuits, and the network bus.

Can a recent jump-start or battery replacement cause this code?

Yes. Voltage spikes or drops during jump-starting or battery servicing can temporarily disrupt network communication and cause modules to log invalid-data codes. If the code does not return and mirror functions are normal, it may have been a transient event.