Faulty or intermittent wiring, connectors, or terminals in the CAN bus circuit to Automated Driving System Control Module B; Failed Automated Driving System Control Module B itself, often due to internal electronic failure; Blown fuse or poor power/ground connection supplying the module; Corrosion or water intrusion at the module connector or in the harness; CAN bus network fault, such as a shorted or open data line, affecting communication; Software or configuration error in the module requiring reprogramming or initialization; Aftermarket accessories improperly tapped into the CAN bus, causing signal disruption

DTC codes / U01xx · Lost communication with a control module / U015D

U015DLost Communication With Automated Driving System Control Module B

U015D is a generic communication fault indicating that the vehicle's main gateway or engine control module has lost contact with the Automated Driving System Control Module B over the controller area network (CAN) bus. The computer has detected a lack of expected periodic messages from that specific module, which is responsible for advanced driver-assistance functions such as lane keeping or adaptive cruise control.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaLost communication with a control module

Symptoms you may notice

Illumination of the malfunction indicator lamp (MIL) or a dedicated driver-assistance warning light
Often no symptoms besides the warning light, especially if the vehicle lacks active driver-assistance features
Inoperative or degraded lane-keeping assist, adaptive cruise control, or automated braking functions
A message on the driver information center stating that driver-assistance systems are unavailable
Intermittent operation of the affected systems, sometimes working after a restart
Other unrelated warning lights if the module shares a bus with other systems

Common causes, most likely first

Faulty or intermittent wiring, connectors, or terminals in the CAN bus circuit to Automated Driving System Control Module B
Failed Automated Driving System Control Module B itself, often due to internal electronic failure
Blown fuse or poor power/ground connection supplying the module
Corrosion or water intrusion at the module connector or in the harness
CAN bus network fault, such as a shorted or open data line, affecting communication
Software or configuration error in the module requiring reprogramming or initialization
Aftermarket accessories improperly tapped into the CAN bus, causing signal disruption

How to diagnose and fix it

Perform a full scan of all modules to confirm U015D is current and check for related communication codes
Inspect the fuse and relay for Automated Driving System Control Module B, and verify battery voltage and ground connections
Visually inspect the module connector and harness for corrosion, damage, or loose pins, especially in areas prone to moisture
Use a digital multimeter to check CAN bus resistance and voltage levels at the module connector, comparing to manufacturer specifications
Perform a wiggle test on the harness while monitoring live data for the module to detect intermittent faults
If wiring and power are good, substitute a known-good module or perform a module reprogramming/initialization per service information
Clear codes and road test to verify the repair, ensuring communication is restored and no codes return

What the code does not always mean

A stored U015D does not automatically condemn the Automated Driving System Control Module B; a poor connection or a fault elsewhere on the CAN bus can prevent its messages from reaching the gateway.
Many vehicles set this code after a battery replacement or low-voltage event, and it may clear after a few drive cycles if the module reinitializes correctly.
Aftermarket dash cams, alarm systems, or phone chargers plugged into the OBD-II port can back-feed the CAN bus and cause communication loss that mimics a module failure.
On some platforms, the module is part of a networked safety system, and a fault in a related module (such as the camera or radar) can cause U015D to set as a secondary code.
A module that communicates intermittently may pass a static resistance test but fail under vibration or temperature changes, so a wiggle test and live data monitoring are essential before replacing parts.

Can I keep driving with U015D?

If the only symptom is a warning light and the vehicle drives normally, you can usually continue driving, but avoid relying on any automated driving features until the fault is repaired. If driver-assistance functions are needed for safety or the vehicle enters a reduced-power mode, have the fault diagnosed 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.