Skip to content
Skanyx

P0202 on Mercedes-Benz: Causes, Symptoms and Fix Cost

Quick Answer

Safe to drive (short-term)

P0202 on a Mercedes-Benz is set when the engine control unit sees an electrical fault in the cylinder 2 injector circuit: an open wire, a short or a coil resistance it does not expect. Cylinder 2 is the second cylinder in from the pulley end on most inline engines, and on a V engine it can sit on either bank depending on the maker. A connector or wiring fault typically costs 65-220 EUR at a workshop to fix; a petrol injector fitted costs about 100-310 EUR.

Severity
Moderate · Fuel System
Typical repair cost, all makes
€5-€650

Connect a standard OBD2 adapter (Bluetooth LE on iPhone) to your Mercedes-Benz and Skanyx tells you what P0202 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.

Get Skanyx free

What does P0202 mean on a Mercedes-Benz?

The Quick Answer above is the generic definition. What follows is the model-specific detail for the Mercedes-Benz models that log P0202.

Mercedes C-Class

2007-2024

On OM651 and other CDI diesels the common-rail injectors are expensive and each carries a calibration code that must be written into the ECU after replacement, a job for XENTRY or a workshop. Petrol M274/M264 engines can throw P0202 from a corroded connector or chafed harness. Skanyx reads the circuit code and freeze frame but not the injector calibration data.

What causes P0202 on a Mercedes-Benz?

Beyond the generic causes listed on the main P0202 page, these are the patterns noted for Mercedes-Benz models:

  • Costly common-rail injector with calibration coding on OM651 CDI diesel

    : Mercedes C-Class

  • Connector corrosion or harness chafe on M274/M264 petrol

    : Mercedes C-Class

How to diagnose P0202 on a Mercedes-Benz with OBD2

  1. Confirm P0202 with Skanyx and note the freeze frame. A matching P0302 means cylinder 2 is actually misfiring; P0264 or P0265 narrows the fault to the control circuit being low or high
  2. Count to cylinder 2. On most inline engines it is the second cylinder from the pulley end, between cylinders 1 and 3. On a V6 or V8 it depends on the maker: engines numbered one bank first (Ford, Audi) put it on bank 1, engines that alternate sides (GM V8s, Toyota's 2GR V6) put it on bank 2
  3. Check the cylinder 2 injector plug: it sits in the middle of the rail, close to the plugs for cylinders 1 and 3, so make sure it is fully latched and was not swapped or left half-seated after earlier work
  4. Unplug the connector and measure the injector coil. Compare with the specification for your engine rather than a generic figure, because port, direct-injection and diesel injectors differ widely
  5. Back-probe the harness from the injector plug to the ECU pin for injector 2, flexing the loom as you go to catch an intermittent break
  6. Swap injector 2 with injector 1 or 3, clear the code and test again. If the code becomes P0201 or P0203, replace the injector; if P0202 stays, repair the wiring or have the ECU driver checked
  7. Direct-injection injectors are fired with a high opening voltage and piezo diesel injectors with far more, so never probe them with a test light or touch the terminals with the engine running

How much does P0202 cost to fix on a Mercedes-Benz? (EUR)

Estimated repair costs for P0202 in EUR, compiled across makes. Expect Mercedes-Benz parts and labour towards the upper end of each range.

Repair Parts Cost Labor Cost Total Estimate DIY Difficulty
Fix cylinder 2 plug or wire yourself (DIY) €5–€30 €0–€0 €5–€30 Moderate
Workshop diagnosis and repair of the cylinder 2 circuit €5–€40 €60–€180 €65–€220 Professional
Fit new cylinder 2 injector - petrol (workshop) €40–€150 €60–€160 €100–€310 Moderate
Fit new cylinder 2 injector - common-rail diesel (workshop) €150–€400 €100–€250 €250–€650 Professional

Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0202 or point to related issues, on any make:

Looking for the full P0202 reference (all makes, full diagnosis flow, complete repair cost matrix)? See the main P0202 guide

Diagnose P0202 on your Mercedes-Benz

Get Skanyx free