Mercedes X Klasse tire pressure ABS steering problem

The symptoms you describe suggest a possible interaction between the tire pressure monitoring system TPMS and the ABS. A significant pressure loss in one or more tires can indeed affect the ABS functionality and power steering, especially if the system relies on wheel speed sensors. Have you checked the actual tire pressures with a gauge to determine the extent of the pressure loss and identify which tire is affected? A simple visual inspection can sometimes miss small punctures. Also, are the tires inflated to the recommended pressure listed on the tire placard?

I have checked the tire pressures manually and discovered a substantial pressure difference in the front passenger side tire compared to the others. While I suspected a slow leak, I am uncertain how a minor pressure loss could cascade into ABS and power steering complications. Could you elaborate on the potential interrelation between these systems, particularly how a defective tire valve or punctured tire influences the ABS module and power steering performance? Also, is it possible a malfunctioning tire sensor could cause these issues even without a true pressure loss?

A significant pressure difference, as you describe, is more than a minor pressure loss and could definitely trigger the described issues. The ABS system relies on consistent wheel speeds for proper operation. A tire with significantly lower pressure will have a different rolling diameter, affecting the wheel speed signal. This discrepancy can confuse the ABS module, causing it to activate erratically or even shut down, hence the warning light. The added stress from the lower pressure tire can also indirectly affect the power steering system's load. While a faulty tire sensor could theoretically cause a false warning, the physical symptoms of vibration and increased steering effort strongly indicate a real pressure loss. Given your observations, I recommend a visit to a qualified workshop to diagnose and rectify the tire issue and assess potential damage to the ABS system. Continuing to drive with a significantly underinflated tire is not advisable.

I appreciate the detailed explanation. Based on your assessment and the confirmed pressure loss, I took the vehicle to a workshop. It was indeed a defective valve in the front passenger side tire, leading to a slow puncture. The valve was replaced, the tire repaired, and the tires inflated to the correct pressure. The ABS light has now extinguished, and the steering feels normal again. The total repair cost was 280€. Thank you for your assistance in clarifying the potential causes and confirming the need for professional intervention.