U1900 on Ford
CAN Communication Bus Fault
U1900 on Ford vehicles indicates can communication bus fault. Au7o has documented this code across 2 Ford models — most commonly on Mustang, Mustang Mach-E. U1900 is a manufacturer-specific network code (commonly Ford) indicating a CAN communication bus fault, often a receive error. The CAN bus is the high-speed network that lets control modules such as the powertrain computer, ABS module, and instrument cluster share data. This code is set when a module stops receiving expected messages from one or more modules on the bus. Because so many systems depend on the network, a bus fault can trigger multiple warning lights and erratic behavior across systems. Typical repair costs on Ford range from $250 to $1,400, depending on the specific model and root cause.
Common Causes of U1900
- •Damaged, corroded, or loose CAN wiring/connectors
- •A failed or offline module pulling down the bus
- •Short to power or ground on a CAN line
- •Open circuit or broken CAN harness
- •Failed instrument cluster or ABS/PCM module
- •Low system voltage or weak battery
- •Water intrusion into a connector or module
U1900 on Ford by Model
Ford Mustang(1 issue)
- 2005-2010 Smart Junction Box Water Intrusion Causing Wiper, Lighting, and Electrical Malfunctions2005-2010
S197 Mustangs are known to suffer from water intrusion at the cowl/windshield area that reaches the Smart Junction Box (SJB)/fuse box, leading to erratic electrical behavior. Owners report inoperative or self-activating wipers, lighting faults, battery drain, no-start conditions, and multiple unrelated electrical issues after rain or car washes. Ford published service information addressing water leak diagnosis and SJB-related corrosion concerns on these cars.
Ford Mustang Mach-E(1 issue)
- SYNC 4A Infotainment Freezing and Spontaneous Rebooting2021-2025
The Mach-E SYNC 4A infotainment system with the 15.5-inch touchscreen experiences freezing, black screens, and spontaneous reboots while driving. Since the touchscreen controls nearly all vehicle functions (climate, charging, drive modes), a frozen or rebooting screen can leave the driver unable to adjust settings or use navigation. The system may take 30-90 seconds to reboot, during which the backup camera and climate controls are unavailable. Ford has released multiple OTA updates to address stability.
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View U1900 across all makes →Frequently Asked Questions
What does U1900 mean on Ford?▼
U1900 stands for "CAN Communication Bus Fault." U1900 is a manufacturer-specific network code (commonly Ford) indicating a CAN communication bus fault, often a receive error. The CAN bus is the high-speed network that lets control modules such as the powertrain computer, ABS module, and instrument cluster share data. This code is set when a module stops receiving expected messages from one or more modules on the bus. Because so many systems depend on the network, a bus fault can trigger multiple warning lights and erratic behavior across systems. On Ford specifically, this code is documented across 2 models.
What causes U1900 on Ford vehicles?▼
Common causes on Ford: Damaged, corroded, or loose CAN wiring/connectors, A failed or offline module pulling down the bus, Short to power or ground on a CAN line, Open circuit or broken CAN harness, Failed instrument cluster or ABS/PCM module. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U1900 on a Ford?▼
Repair costs on Ford range from $250 to $1,400, depending on the specific model and root cause.
Which Ford models have U1900 documented?▼
Au7o has documented U1900 on 2 Ford models: Mustang, Mustang Mach-E.