U029F — Lost Communication With Evaporative Emission System Leak Detection Control Module

What Does U029F Mean?

U029F is a diagnostic trouble code indicating: Lost Communication With Evaporative Emission System Leak Detection Control 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 U029F

⚠️ Check Engine Light (MIL) illuminated
⚠️ No communication with Evaporative Emission System Leak Detection Control 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 Evaporative Emission System Leak Detection Control Module
🔍 Power or ground supply issue to Evaporative Emission System Leak Detection Control Module
🔍 Evaporative Emission System Leak Detection Control Module internal failure
🔍 Water intrusion damaging module or connectors
🔍 CAN bus termination resistor fault

Frequently Asked Questions

What does U029F mean?

U029F indicates: Lost Communication With Evaporative Emission System Leak Detection Control Module. The vehicle's computer has detected that the Evaporative Emission System Leak Detection Control Module is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U029F?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U029F for extended periods may cause additional problems.

How much does it cost to fix U029F?

Repair costs for U029F 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 Evaporative Emission System Leak Detection Control Module for damage
🔧 Check power and ground supply to Evaporative Emission System Leak Detection Control Module
🔧 Replace failed Evaporative Emission System Leak Detection Control Module

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.

U029F: Lost Communication With Evaporative Emission System Leak Detection Control Module