P00AF Turbocharger/Supercharger Boost Control A Module Performance

Boost control A here is an electronic actuator with its own electronics (a "smart" actuator), usually on the variable turbine geometry, with its own position sensor and controlled over a data bus or a pulsed signal. It checks itself and reports internal faults to the engine control module; documented examples are pattern errors, overcurrent and checksum errors. The control module cannot narrow down a fault inside the actuator further. P00AF is set when actuator A reports such an internal fault. Manufacturer bulletins recommend checking the vane mechanism for free movement and, if it moves freely, replacing only the actuator rather than the whole turbocharger.

Likely causes

Symptoms

• Check engine light on
• Loss of power or limp mode with reduced boost
• Often stored with actuator position or boost codes

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.