U0183
UniversalLost Communication With Rear Lighting Control Module
The vehicle has detected that it is not receiving expected communication from the rear lighting control module. That module may manage some rear lights, but its exact functions vary by vehicle. The communication fault could affect rear lighting or set a warning, though the code alone does not prove the module has failed and there may be no noticeable symptoms.
⚠️ Before You Begin (Safety First)
Check that the brake, turn, tail, and other required rear lights work before driving. If brake or turn lights are not working, or rear lighting is unreliable, do not drive in traffic until the fault is assessed; arrange repair or towing as appropriate. Avoid probing wiring or disconnecting modules unless the vehicle-specific service procedure calls for it.
Common Symptoms
- Some rear lights may not operate if their control depends on the affected module.
- A lighting or communication warning may appear, depending on the vehicle.
- Several rear lighting functions may behave inconsistently if communication is intermittent.
- There may be no noticeable symptoms if the fault is intermittent or the vehicle's lighting functions are handled another way.
Common Causes
- A loose, damaged, corroded, or poorly connected module connector may interrupt communication.
- A wiring fault in the vehicle network may prevent messages from reaching or leaving the module.
- A fuse, power supply, or ground problem may stop the module from operating or communicating.
- Low or unstable vehicle voltage may contribute to intermittent communication faults.
- The rear lighting control module itself may have failed, but this should be confirmed by testing.
- A fault elsewhere on the vehicle network may disrupt communication with this module.
Diagnostic Steps
- With the vehicle parked safely, check the brake, turn, tail, and other rear lights with help from another person; note which functions do not work.
- Check the owner's manual for relevant lighting or module fuses and inspect them only as described there. Replace a fuse only with the specified type and rating; if it blows again, stop and seek diagnosis.
- With the ignition off, visually inspect accessible rear-light and module-area connectors for obvious damage, moisture, or loose connections. Do not pull on wiring or unplug modules without vehicle-specific instructions.
- If available, use a compatible scan tool to check whether the code is current or stored and whether other modules report communication faults.
- If lights are inoperative, wiring is damaged, a fuse repeatedly fails, or the code returns, have a qualified technician test the module power, ground, and communication circuits.
When to Call a Professional
A technician can scan all vehicle modules to determine whether this code is current or intermittent and check for related communication or power-supply faults. Diagnosis may include inspecting the module's power, ground, connectors, and network wiring, then confirming communication and checking commanded lighting operation using vehicle-specific service information. The code alone is not enough to justify replacing the module.
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.
Commonly Asked Questions
Does U0183 prove that the rear lighting control module is faulty?
No. It indicates lost communication with that module. A power, ground, connector, wiring, or broader network problem can cause the same condition, so diagnosis is needed before replacing a part.
Can the vehicle still be driven with this code?
That depends on whether required rear lights work reliably. Check the lights before driving. If brake or turn lights are inoperative, or lighting is unreliable, do not drive in traffic until the problem is assessed.
Why might there be no warning or obvious lighting problem?
The fault may be intermittent, or the vehicle may retain some lighting functions despite losing communication. Exact behavior depends on the vehicle's design.
What should be checked before replacing the module?
A technician should check for related codes, confirm the communication fault, and inspect the module's power, ground, connectors, and network wiring using vehicle-specific service information.
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.