W213 220d restricted performance mode

[paulh2602601]

Greetings to all,

I am seeking assistance regarding an issue I am experiencing with my vehicle, as I find myself utterly at a standstill.

I encountered a problem with the gearbox, displaying fault code P073E00, which is evidently a recognised issue. The gearbox was overhauled to rectify the issue, and subsequently, all functions resumed flawlessly.

The gearbox lubricant was replenished in accordance with the manufacturer’s specifications, and the gearbox calibration was performed promptly thereafter.

Nonetheless, as I entered the motorway to evaluate the vehicle, I accelerated aggressively during the merge. I observed that when the engine attained approximately 4,000 RPM, it ceased to rev and the vehicle abruptly entered limp mode. It appears to retain approximately 90% of its efficacy, yet the problem is distinctly apparent.

It is peculiar that the vehicle operates flawlessly in all other respects. The gearbox operates seamlessly, and there are no issues during standard driving.

If I turn off the vehicle and then restart it, all functions return to normal and the car operates flawlessly once more. Nonetheless, if this occurs repeatedly, the engine management light (EML) will ultimately illuminate.

I examined the vehicle and the diagnostic code displayed is P054496, which pertains to the temperature sensor 1 within the exhaust system.

I originally suspected that this sensor could be the source of the issue, thus I substituted the sensor. Regrettably, the issue persists.

I am contemplating whether P054496 is genuinely responsible for the limp mode, or if there might be an alternative underlying problem triggering this fault code.

Has anyone encountered a comparable issue, specifically a vehicle that enters limp mode at approximately 4,000 RPM with fault code P054496?

Any suggestions or insights would be immensely valued, as I find myself utterly perplexed by this issue at present.

I appreciate your assistance in advance! 🙏

[Black_raven]

Is it a foolish inquiry to suggest that 4000 rpm is the maximum for a diesel engine, with minimal advantages in exceeding that limit?

Have you inspected the wiring connected to the sensor, and was it an authentic sensor provided by Mercedes?

[paulh2602601]

The sensor malfunction arises because the RPM momentarily stabilises for approximately half a second, leading to a rapid temperature increase. I do not believe that the sensor itself is inherently the issue. I sense that there remains an issue with the TCU post-reconstruction, despite the gearbox functioning flawlessly otherwise.

It occurs solely in the 5th, 6th, 7th, 8th, and 9th gears. Upon aggressive acceleration, as the engine attains elevated RPM levels just prior to the anticipated shift, it enters limp mode.

I am contemplating whether there may still be a problem with the TCU or its internal sensors, rather than the sensor itself.

[Rudy7831]

interesting info