Good morning, everyone,

Today we are reporting the case of this Smart Fortwo 0.9 turbo 66 kw from 2017: the carburetion was very fat with black exhaust smoke even though there were no errors in the ECU.

Checks revealed a technical bulletin with the same complaint and also the possible presence of errors, according to which the defective oxygen sensor 1 was the root cause.

Bulletin

However, by replacing the lambda sensor that can be seen when opening the engine crankcase, the fault is not resolved.

In fact, due to a strange turn of the exhaust gases that cannot be seen because it is covered by iron casings, the upstream lambda sensor was not the one replaced, but the lower one with five wires.

Here you will find both the reference bulletin and the procedures for disassembling the two lambda sensors in order to identify them correctly.

SMART FORTWO III (453) - 0.9 Turbo (66Kw) from 09-2014 onwards 281910 - ENGINE ELECTRICAL SYSTEM - REMOVAL-REMOUNTING

We would like to thank the GIUSSANI AUSONIO workshop in Erba for the report and on behalf of the Technical Help Desk team wish you good work

• SMART FORTWO III (453) - 0.9 Turbo (66Kw) from 09-2014 onwards 281910 - ENGINE ELECTRICAL SYSTEM - REMOVAL-REMOUNTING (EN - translation in progress, please try again in a few minutes)
• Bulletin (EN - translation in progress, please try again in a few minutes)