P05F6

Exhaust Aftertreatment Power Relay Control Circuit Stuck On

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$11–56 (est.)

Symptoms

AdBlue/SCR system components operate when the ignition is switched off
Battery drain overnight
Check Engine Light Is On
Overconsumption of AdBlue reagent
Increased wear on the pump and system heaters

Causes

Welded or stuck power relay contacts
Contamination of relay contacts (arc wear)
Poor quality relay with a defective contact group
Long-term operation of the relay at high current (overload)

How to Fix

Check the presence of voltage at the relay output with the ignition off
Remove the aftertreatment system power relay - the components should stall.
Measure the resistance between the contacts of the removed relay (welding - close to zero)
Replace the aftertreatment system power relay
After replacement, check the current consumption with the ignition off
Make sure there are no other system codes

Related codes

P05F7 P05F3 P05F4 P05F5 P20E8