U01A4 — Lost Communication With Hybrid/EV Battery Interface Control Module E

What Does U01A4 Mean?

U01A4 is a diagnostic trouble code indicating: Lost Communication With Hybrid/EV Battery Interface Control Module E. This code relates to the network communication system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of U01A4

⚠️ Check Engine Light (MIL) illuminated
⚠️ No communication with Hybrid/EV Battery Interface Control Module E
⚠️ 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 Hybrid/EV Battery Interface Control Module E
🔍 Power or ground supply issue to Hybrid/EV Battery Interface Control Module E
🔍 Hybrid/EV Battery Interface Control Module E internal failure
🔍 Water intrusion damaging module or connectors
🔍 CAN bus termination resistor fault

Frequently Asked Questions

What does U01A4 mean?

U01A4 indicates: Lost Communication With Hybrid/EV Battery Interface Control Module E. The vehicle's computer has detected that the Hybrid/EV Battery Interface Control Module E is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U01A4?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U01A4 for extended periods may cause additional problems.

How much does it cost to fix U01A4?

Repair costs for U01A4 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 Hybrid/EV Battery Interface Control Module E for damage
🔧 Check power and ground supply to Hybrid/EV Battery Interface Control Module E
🔧 Replace failed Hybrid/EV Battery Interface Control Module E

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.

U01A4: Lost Communication With Hybrid/EV Battery Interface Control Module E