What Does P00AF Mean?
The PCM has detected a performance issue with the turbocharger/supercharger boost control module 'A'. This code specifically targets the electronic control module (not the mechanical actuator) that manages boost pressure. The module is failing to respond correctly to PCM commands, producing incorrect boost levels, or reporting errors in its internal diagnostics. The driver may notice inconsistent boost, reduced power, overboost or underboost conditions, and a check engine light.
Common Causes
35%
Failed or malfunctioning boost control module 'A' (electronic actuator controller)
25%
Communication fault between the PCM and the boost control module (CAN bus or dedicated wiring issue)
20%
Mechanical binding or restriction in the wastegate or VGT vanes preventing the module from achieving target position
12%
Power supply or ground issue to the boost control module
8%
Software calibration mismatch after module replacement or update
Diagnostic Steps
1
Read all DTCs from both the PCM and the boost control module itself — additional codes may narrow down whether the fault is communication, electrical, or mechanical.
2
Monitor commanded vs. actual boost pressure PIDs during moderate acceleration — a significant deviation (more than 3 psi) indicates the control system cannot achieve its target.
3
Check the boost control module power supply (battery voltage) and ground circuit — measure voltage drop on both with the module commanding the actuator (should be less than 500 mV).
4
Inspect the wastegate or VGT actuator linkage for binding, carbon buildup, or corrosion that would prevent free movement — manually cycle the actuator with the scan tool and listen/watch for smooth, full travel.
5
Check CAN bus communication lines (if applicable) between the PCM and boost module for proper termination resistance (typically 60 Ω between CAN-H and CAN-L at the module connector).
6
If the module has been recently replaced, verify it has been properly coded/adapted to the vehicle using the manufacturer's diagnostic software.
Estimated Repair Cost
$300 - $1,500
Parts + labor, varies by vehicle and location
The PCM has detected a performance issue with the turbocharger/supercharger boost control module 'A'. This code specifically targets the electronic control module (not the mechanical actuator) that manages boost pressure. The module is failing to respond correctly to PCM commands, producing incorrec...
The most common cause of P00AF (Turbocharger/Supercharger Boost Control "A" Module Performance) is: Failed or malfunctioning boost control module 'A' (electronic actuator controller)
Typical repair costs for P00AF range from $300 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Drive with caution. An uncontrolled boost system can produce overboost (engine damage risk) or underboost (loss of expected power). If you notice surging, loud turbo noises, or significant power loss, stop driving and have the vehicle towed for diagnosis.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P00AF to identify the root cause.
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Quick Info
Category
Powertrain
System
Forced Induction / Turbocharger System
Difficulty
Type
Generic (SAE)
Recommended Tools
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