U1900Network Communication

CAN Communication Bus Fault

U1900 is a manufacturer-specific code indicating a general fault on the CAN communication bus. It usually reflects a communication problem detected by a module.

🚗 Depends. A general bus fault can affect multiple systems, so diagnose before extended driving.
MEDIUM
severity
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🎯 Top Causes, Ranked by Likelihood

#1CAN bus wiring or connector fault$50-$400
35%
Open, shorted, or corroded wiring interrupts the CAN bus.
#2Failed or offline module$200-$900
30%
A module that stops communicating causes a general bus fault.
#3Poor grounds or power supply$50-$300
20%
Weak grounds cause communication problems across modules.
#4Intermittent connection$50-$300
15%
A loose or vibrating connection causes intermittent faults.

🩺 Common Symptoms

💰 Repair Cost: DIY vs Shop

DIY Cost
$50-$400
Shop Cost
$150-$900

📋 Free OBD2 Code Cheat Sheet

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🔧 How to Diagnose U1900

1Scan all modules and note which are offline
2Inspect CAN wiring, connectors, and grounds
3Check CAN resistance and voltage
4Isolate any module dragging the bus down

❓ Frequently Asked Questions

Can I drive with U1900?
It depends on which systems are affected. Since it is a general bus fault, get it diagnosed.
Is U1900 generic?
It is manufacturer-specific but commonly used to flag a general CAN bus communication problem.
What causes U1900?
CAN wiring faults, a failed module, or poor grounds and power are the usual causes.

🔗 Related Codes

U1000U0001U0073U0100
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