U02B3 — Lost Communication With Driver Monitoring System Module

What Does U02B3 Mean?

U02B3 is a diagnostic trouble code indicating: Lost Communication With Driver Monitoring System Module. This code relates to the manufacturer-specific network system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of U02B3

⚠️ Check Engine Light (MIL) illuminated
⚠️ No communication with Driver Monitoring System Module
⚠️ Multiple warning lights may illuminate simultaneously
⚠️ Related system completely inoperative
⚠️ Multiple warning lights on dashboard

Common Causes

🔍 CAN bus wiring fault (open or shorted) to Driver Monitoring System Module
🔍 Power or ground supply issue to Driver Monitoring System Module
🔍 Driver Monitoring System Module internal failure
🔍 Water intrusion damaging module or connectors
🔍 CAN bus termination resistor fault

Frequently Asked Questions

What does U02B3 mean?

U02B3 indicates: Lost Communication With Driver Monitoring System Module. The vehicle's computer has detected that the Driver Monitoring System Module is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U02B3?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U02B3 for extended periods may cause additional problems.

How much does it cost to fix U02B3?

Repair costs for U02B3 typically range from $80 to $1200, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect CAN bus wiring to Driver Monitoring System Module for damage
🔧 Check power and ground supply to Driver Monitoring System Module
🔧 Replace failed Driver Monitoring System Module

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

U02B3: Lost Communication With Driver Monitoring System Module