Peugeot 807 Tire Pressure ABS and Steering Issues

The symptoms you describe are certainly cause for concern. A defective tire valve could be the culprit behind the low tire pressure initiating the chain of events. However, the ABS and power steering issues suggest a more complex interaction. Is the tire losing pressure rapidly? Have you inspected the tires for punctures or damage?

The pressure loss appears gradual, not a sudden flat. I visually inspected the tires; no obvious punctures are visible. Given the ABS involvement, could a faulty tire valve reliably trigger these cascading failures, or are there alternative explanations I should be considering before pursuing valve replacement?

While a gradual pressure loss from a faulty valve can trigger the tire pressure warning, the additional ABS and power steering issues warrant professional diagnosis. It is possible the low pressure is affecting ABS sensor readings or hydraulically linked systems. The safest course is a workshop visit to pinpoint the root cause. Continuing to drive with these symptoms presents a safety risk.

Thank you for the insights. I followed your advice and brought it to a workshop. The diagnosis confirmed a defective tire valve leading to low tire pressure which, in turn, compromised the ABS and power steering systems. The repair, including valve replacement and system recalibration, cost 280€. Your assessment was accurate and greatly appreciated.