Code Mercedes-Benz Injectors (IMA IQA) with YOUCANIC Scanner – Fix Rough Idle, Smoke & CEL

About this video

In this step-by-step video, we show how to code (enter IMA/IQA codes for) Mercedes-Benz diesel fuel injectors using the YOUCANIC UCAN-II scanner. After installing new or reman injectors, the ECU needs the unique calibration code for each cylinder. Without coding, the engine may run rough, smoke, or keep the Check Engine Light on.

Note: This is injector coding for the engine fuel injectors, not the AdBlue/DEF injector. For Y129 (DEF metering valve) teach-in, see our separate video.

Want the full guide with photos, tools, and step-by-step help for this scanner demo?

👉 https://www.youcanic.com/how-to-perform-injector-coding-with-a-youcanic-scanner/

At YOUCANIC, we’re on a mission to make car repair knowledge accessible to everyone so you can fix your own car, save money, and understand what’s really going on under the hood.

Why injector coding is needed

Each injector has a unique IMA/IQA calibration code that tells the ECU its precise flow characteristics.

Coding ensures correct fueling, smoother idle, proper emissions, and prevents correction values from maxing out.

Symptoms you may have before coding (or with wrong codes)

Rough/unstable idle, vibration, or hard starts

Black smoke, poor fuel economy, sluggish performance

Check Engine Light with injector balance/trim or misfire faults

Strong diesel smell, knocking/ticking at idle (post-replacement)

Common DTCs related to injector issues (examples; vary by model)

P0263–P0272: Cylinder contribution/balance

P0201–P0206: Injector circuit faults

P030X: Misfires, P2A00/P2A01 (mixture), fuel trim/rail pressure related faults

DIY tips

Code each cylinder to match the injector installed (Cylinder 1 location differs by engine—check your layout).

Input the code exactly as printed (watch for 0 vs O, 1 vs I).

If the ECU won’t accept a code, confirm the injector part