G Klasse ECU Issues and Resolution

That's quite the predicament with a G Klasse. Reduced engine power and ECU errors are never pleasant. Before replacing the entire unit, which can be costly, have you attempted a system reset? Sometimes, automotive electronics can act up due to transient voltage fluctuations or software glitches. It's worth exploring. Could you specify the exact error code retrieved during your car diagnostics? That detail could provide valuable clues. It reminds me of an issue I had with an older S-Class where a faulty sensor was throwing off the ECU, causing similar symptoms. Did you check all the sensors?

I did try a basic system reset by disconnecting the battery, but the error persists. The error code I retrieved was P0606 (ECU Processor Fault). I considered it may be a faulty sensor, but given the error code, I focused on the ECU. I have not checked all sensors. Is there a specific procedure you recommend for a more comprehensive system reset involving the vehicle electronics, or perhaps a way to definitively rule out sensor issues before concluding it's the ECU?

P0606 indeed suggests an internal ECU malfunction. While a more comprehensive system reset might address temporary software corruption, the likelihood of it resolving a processor fault is quite low. Given the error code, it's advisable to consult a qualified Mercedes-Benz technician. It's possible a software reflash could resolve the issue, but attempting this without the proper equipment and expertise can lead to further complications. From my experience with automotive electronics, attempting a self-repair on the ECU when it shows a processor fault can lead to further damages. They will be able to diagnose the vehicle electronics properly.

I appreciate your input. It seems my initial assessment was accurate. I took the G Klasse to a certified technician, and after thorough car diagnostics, they confirmed the main relay was indeed defective, causing the ECU to malfunction. Replacing the relay and performing a system reset resolved the issue. The final repair cost was 120€. Thanks again for the cautious advice.