P05F6 — Exhaust Aftertreatment Power Relay Control Circuit Stuck On

What Does P05F6 Mean?

P05F6 is a diagnostic trouble code indicating: Exhaust Aftertreatment Power Relay Control Circuit Stuck On. This code relates to the vehicle speed and idle control system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P05F6

⚠️ Check Engine Light (MIL) illuminated
⚠️ Exhaust Aftertreatment Power Relay remains active when it should be off
⚠️ Related system running continuously
⚠️ Erratic idle speed

Common Causes

🔍 Exhaust Aftertreatment Power Relay mechanically stuck in active position
🔍 Short circuit holding Exhaust Aftertreatment Power Relay control on
🔍 Faulty Exhaust Aftertreatment Power Relay driver circuit in ECM/PCM

Frequently Asked Questions

What does P05F6 mean?

P05F6 indicates: Exhaust Aftertreatment Power Relay Control Circuit Stuck On. The vehicle's computer has detected that the Exhaust Aftertreatment Power Relay is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P05F6?

Only short distances if absolutely necessary. P05F6 affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix P05F6?

Repair costs for P05F6 typically range from $50 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 Exhaust Aftertreatment Power Relay for mechanical binding or debris
🔧 Replace stuck Exhaust Aftertreatment Power Relay
🔧 Check Exhaust Aftertreatment Power Relay control circuit for short

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.

P05F6: Exhaust Aftertreatment Power Relay Control Circuit Stuck On