A blown fuse or poor power/ground connection at the antenna control module; Damaged or corroded wiring between the antenna control module and the network bus; A failed antenna control module itself, often due to water intrusion or internal circuit failure; Loose or backed-out pins in the module connector or a damaged connector housing; A network bus fault, such as a shorted or open data line, that isolates the antenna control module; A weak or failing battery or charging system causing low-voltage communication dropouts

DTC codes / U01xx · Lost communication with a control module / U0185

U0185Lost Communication With Antenna Control Module

Q: What does code U0185 mean?

Lost Communication With Antenna Control Module. U0185 means the vehicle's network lost communication with the antenna control module, which is the unit that manages radio antenna functions such as signal amplification and diversity switching. The computer detected that the module stopped responding to periodic network messages, so it flagged the missing node rather than a specific antenna fault.

U0185 means the vehicle's network lost communication with the antenna control module, which is the unit that manages radio antenna functions such as signal amplification and diversity switching. The computer detected that the module stopped responding to periodic network messages, so it flagged the missing node rather than a specific antenna fault.

SystemNetwork

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaLost communication with a control module

Symptoms you may notice

A warning light or message on the dashboard indicating a communication or module fault
The radio may lose reception, show poor AM/FM sensitivity, or fail to switch antenna diversity
Often no symptoms besides the warning light, especially if the radio still receives strong local stations
Intermittent radio static or dropping signal that correlates with rough roads or temperature changes
Other modules on the same network may log unrelated communication codes if the bus is disturbed

Common causes, most likely first

A blown fuse or poor power/ground connection at the antenna control module
Damaged or corroded wiring between the antenna control module and the network bus
A failed antenna control module itself, often due to water intrusion or internal circuit failure
Loose or backed-out pins in the module connector or a damaged connector housing
A network bus fault, such as a shorted or open data line, that isolates the antenna control module
A weak or failing battery or charging system causing low-voltage communication dropouts

How to diagnose and fix it

Check all fuses that supply the antenna control module and confirm battery voltage is stable with the engine off and running
Inspect the antenna control module connector for corrosion, water intrusion, loose pins, and secure mounting
Measure power and ground at the module connector with a multimeter while wiggling the harness to catch intermittent faults
Check network bus continuity and resistance from the module connector to the main bus, looking for opens or shorts
Clear the code and perform a network communication self-test to see whether U0185 returns immediately or only after a road test
If wiring and power are good, substitute a known-good antenna control module and recheck communication before condemning the original
After repair, verify the radio antenna functions and confirm no communication codes return after a full drive cycle

Antenna module codes that fool good technicians

A radio that still plays clearly does not rule out U0185, because the antenna control module can fail on the network side while the antenna signal path continues to work.
Water intrusion into the antenna module or its connector is a common hidden cause, especially on vehicles with antennas mounted in glass or rear quarter panels.
A weak battery or failing alternator can set U0185 along with other communication codes, so always check charging system health before replacing modules.
The antenna control module is often confused with the radio head unit, but U0185 points to the separate antenna module and its network connection.
A single shorted module on the network bus can pull down communication for several nodes, so inspect bus voltage and resistance before assuming the antenna module is at fault.

Can I keep driving with U0185?

The vehicle is generally safe to drive because U0185 affects radio antenna communication rather than engine, steering, or braking systems. Avoid relying on the radio for traffic or emergency information until the fault is repaired, and address any other communication codes promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.