Exhaust Aftertreatment Power Relay Control Circuit Stuck On

Common symptoms

What you'll notice

• Check the wiring connections to the exhaust aftertreatment power relay and ensure they are secure and free of any damage.
• Inspect the exhaust aftertreatment power relay for any signs of malfunction or damage and replace it if necessary.
• Test the exhaust aftertreatment power relay control circuit for any voltage irregularities and repair or replace any faulty components.

Common causes

Most likely first

1. Faulty exhaust aftertreatment power relay
2. Electrical short circuit in the exhaust aftertreatment power relay circuit
3. Malfunctioning exhaust aftertreatment power relay control module
4. Loose or damaged wiring connections in the exhaust aftertreatment power relay circuit
5. Failure of the engine control unit (ECU) to communicate with the exhaust aftertreatment power relay control module

How to diagnose & fix

Work through it in order

1. Malfunction indicator light (MIL) is permanently illuminated
2. Poor fuel efficiency or decreased engine performance
3. Difficulty starting the vehicle
4. Increased exhaust emissions or black smoke from the exhaust pipe
5. Limited vehicle power or reduced acceleration.