An OBD (on-board diagnosis) system of the second generation uses OBD II. In Europe, the OBD II, with appropriate adaptation for the European market, is called European On-Board Diagnosis (EOBD).

The OBD system is integrated in the ECM and constantly monitors all emissions-relevant components and systems of the vehicle.

The OBD has the following tasks:

Monitor emissions- relevant components and systems while traveling
Identify and store malfunctions
Display of malfunctions via the engine diagnosis indicator lamp (Malfunction Indicator Lamp)
Detected faults are transmitted over a uniform interface (diagnostic connector) to a diagnostic unit (e.g. CONSULT)

OBD follows the list as below:

Ensuring permanently low exhaust emissions
Protect components at risk (such as catalytic converters) against backfires

The following components and systems are monitored:

Catalytic converter heating
Smooth running analysis (recognition of combustion misfire)
Oxygen sensors
Purge control
Smooth running control
Other components which related to emission or which can cause malfunction in the diagnosis of other components.
Efficiency of the CAT (catalytic converter function)

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Diagnosis Description: Description

Use the Manual With the Right Hardware

When to See a Mechanic