U3506 — Control Module Input Power B Circuit High

What Does U3506 Mean?

U3506 is a diagnostic trouble code indicating: Control Module Input Power B Circuit High. This code relates to the vehicle systems system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of U3506

⚠️ Check Engine Light (MIL) illuminated
⚠️ Control Module Input Power B reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ System warning light illuminated

Common Causes

🔍 Short to voltage in Control Module Input Power B wiring harness
🔍 Corroded or water-damaged Control Module Input Power B connector
🔍 Faulty Control Module Input Power B outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does U3506 mean?

U3506 indicates: Control Module Input Power B Circuit High. The vehicle's computer has detected that the Control Module Input Power B is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U3506?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U3506 for extended periods may cause additional problems.

How much does it cost to fix U3506?

Repair costs for U3506 typically range from $20 to $300, 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 and repair Control Module Input Power B wiring for short to voltage
🔧 Clean or replace corroded Control Module Input Power B connector
🔧 Replace faulty Control Module Input Power B

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.

U3506: Control Module Input Power B Circuit High