U0180: Lost Communication with Automatic Lighting Control Module

What it means

The Automatic Lighting Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Automatic exterior lighting (auto headlamps) stops working. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.

How it works

The Automatic Lighting Control Module manages automatic exterior-lighting functions, such as switching the headlamps based on vehicle inputs. U0180 is stored when other modules stop receiving its network messages for the required time, often because the module has lost power or ground, its CAN wiring is faulty, or the gateway cannot route its messages.

Common causes

Most likely first.

1. Headlamp control module unpowered
2. CAN wiring to headlamp module broken
3. Gateway module routing CAN messages incorrectly

Symptoms

• Automatic lighting functions may be unavailable
• Other communication codes

How to diagnose it

1. Scan all modules and review freeze-frame data for U0180 and related network codes to determine whether the fault is limited to the lighting module.
2. Check whether automatic headlamp operation is unavailable and whether other lighting functions still work.
3. Use vehicle service information to locate the Automatic Lighting Control Module and inspect its connector and CAN wiring for damage, corrosion, loose pins, or disconnection.
4. Check module power and ground against the manufacturer's specification.
5. Test the CAN wiring and check for gateway communication or routing faults using the manufacturer's procedure.
6. If power, ground, wiring, and gateway checks pass, test the Automatic Lighting Control Module according to the manufacturer's diagnostic procedure.

Common fixes

• Restore power or ground to the Automatic Lighting Control Module by repairing a faulty feed or connection.
• Repair damaged CAN wiring or secure a loose or corroded connector.
• Correct a confirmed gateway routing fault.
• Replace the module if the manufacturer's tests confirm an internal failure.

Can I keep driving?

Automatic headlamp control may not work, so use the manual light controls and make sure the required lights are on in poor visibility or at night. The fault does not by itself indicate an engine problem.