Mercedes CLA C118 (2021) — OBD-II port location | DVI Reports

Mercedes · OBD-II

Mercedes CLA C118 (2021) — Where is the OBD-II port?

Below the dashboard, driver area

Open the driver door and look into the driver footwell. Find the diagnostic connection below the outer left dashboard, near the bonnet-release area. The manual highlights the socket below the dashboard and shows the diagnostic plug connecting upward. Check the cited manual and exact vehicle configuration.

How to find it

1. Check the generation and year range above. Dashboard design and location can vary by market and version.
2. Below the dashboard, driver area. Source landmarks: bonnet release.
3. Use a torch to identify the socket. Do not dismantle the dashboard to search for it.
4. Identify the trapezoidal 16-position socket. Switch the ignition off before connecting an adapter, then follow the scanner instructions.

Source and identification documentation

Source: Mercedes-Benz CLA C118 Operator’s Manual, March 2021 — p27. Accessed 30/10/2026. Check the documentation against your vehicle configuration before connecting.

• Open the driver door and look into the driver footwell.
• Find the diagnostic connection below the outer left dashboard, near the bonnet-release area.
• The manual highlights the socket below the dashboard and shows the diagnostic plug connecting upward.

Looking for a sensor?

Sensor positions depend on the engine code. For DPF, EGR, MAF or MAP components, use documentation for the exact engine. We do not infer location from model alone.

Sensor orientation guides · MAF, MAP, EGR and DPF

General orientation only, NOT verified locations for a specific vehicle. Exact identification requires engine code, year and technical documentation.

MAF · Mass airflow sensor

Usually on the intake duct after the air filter and before the turbo or throttle, if fitted.

MAP · Manifold pressure sensor

Usually on the intake manifold or charge-air pipe. A separate boost pressure sensor may also be fitted.

EGR · Exhaust gas recirculation valve

Near the exhaust-to-intake recirculation path; some engines have EGR coolers and multiple circuits.

DPF · DPF differential pressure sensor

Often in the engine bay or underbody, connected by two small pressure lines across the particulate filter. Exact placement depends on engine.

Do not disconnect sensors, DPF lines or hot components to identify them. Codes are diagnostic examples, not proof of a fault.