DTC Code Index: Every Fault Code Covered on Akotex
A quick-navigation index of every diagnostic trouble code covered on this site. Each code links to every part of its guide, in order — from what the code means, through root-cause diagnosis, to the actual repair. New to DTCs? Start with DTC Basics: How Diagnostic Trouble Codes Are Structured before diving into a specific code below.
P00AF — Turbocharger Boost Control (Wastegate Actuator Position Error)
The ECU commands the wastegate actuator to a specific position and compares it against actual feedback. When the actuator can’t reach, move to, or hold that position — often due to a seized wastegate lever — the ECU stores P00AF and triggers the EPC light and limp mode.
- How I Saved $4,500 by DIY-ing My VW Sportwagen IS12 Turbocharger — the original P00AF diagnosis and repair, start to finish
Related reading:
Car Lost Power While Driving on Highway? From Boost to Limp Mode
Understanding the IS12 Turbocharger: Location and Component Breakdown
VCDS Scanner: The Tool I Used to Fix My EPC Light Issue
P0234 — Turbocharger/Supercharger “A” Overboost Condition
The opposite of P0299: instead of too little boost, the ECU detects that actual boost pressure exceeds what it requested. Often mistaken for turbocharger failure, but the real cause is frequently a sticking wastegate, actuator calibration issue, or MAP sensor problem.
- Part 1: P0234 Explained — How EA888 Turbo Boost Control Works and Why Overboost Occurs
- Part 2: P0234 Diagnosis and Repair — Troubleshooting Turbocharger Overboost Step by Step
Related reading:
P0299 Explained: Diagnosing Turbo Underboost
IS12 Wastegate Actuator Calibration and Adaptation
P0299 — Turbocharger/Supercharger Underboost Condition
One of the most common — and most misdiagnosed — codes on the EA888 platform. Owners often assume turbo failure; in most cases, the real cause is elsewhere in the boost system.
- Part 1: P0299 Explained — How the EA888 Turbo System Works and How the Code Is Set
- Part 2: P0299 Explained — Diagnosing Turbo Underboost (Boost Leaks, Diverter Valve, Wastegate, PCV, MAP Sensor & More)
- Part 3: Hands-On Diagnostic Process (freeze-frame data, live boost readings, VCDS testing strategy) — coming soon
P334A — Charge Pressure Actuator Electrical Malfunction
Despite the word “Electrical” in the code description, P334A is frequently a mechanical fault masquerading as an electrical one. This three-part series walks through the full diagnostic-to-repair process.
- Part 1: Error Code P334A — The Complete Guide — what the code means and why “electrical” is misleading
- Part 2: DTC P334A — Root Causes and Diagnosis — systematic root-cause testing
- Part 3: P334A Repair Procedures, Wastegate Actuator Calibration and Adaptation — the fix, plus required VCDS adaptation
Related reading: IS12 Wastegate Actuator Calibration and Adaptation (Bench Calibration and ECU Adaptation Procedure)
Diagnostic Tool Comparisons
Not a DTC itself, but essential reading for pulling and confirming any code on this list:
This index is updated as new fault code guides are published. Bookmark this page to keep track of new additions to the library.