U02B4 — Lost Communication With Front Radar Module A

What Does U02B4 Mean?

U02B4 is a diagnostic trouble code indicating: Lost Communication With Front Radar Module A. 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 U02B4

⚠️ Check Engine Light (MIL) illuminated
⚠️ No communication with Front Radar Module A
⚠️ 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 Front Radar Module A
🔍 Power or ground supply issue to Front Radar Module A
🔍 Front Radar Module A internal failure
🔍 Water intrusion damaging module or connectors
🔍 CAN bus termination resistor fault

Frequently Asked Questions

What does U02B4 mean?

U02B4 indicates: Lost Communication With Front Radar Module A. The vehicle's computer has detected that the Front Radar Module A is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U02B4?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U02B4 for extended periods may cause additional problems.

How much does it cost to fix U02B4?

Repair costs for U02B4 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 Front Radar Module A for damage
🔧 Check power and ground supply to Front Radar Module A
🔧 Replace failed Front Radar Module A

1
Find your vehicle above
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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.

U02B4: Lost Communication With Front Radar Module A