[Prefferle]

Originally Posted by MikkiJayne

The D2 and C5 A6 will log the same fault in certain conditions, and it puts the ESP on and the engine in reduced power mode when it happens. I've had the issue in both - an incorrectly adjusted switch in the S8, and a faulty switch in the A6. The A6 uses the same ratchet-type switch as the D3.

It might be worth removing the switch, reset the mechanism and reinstall before chasing wiring issues.

Hello again,
so I’ve disconnected ABS Module plug, no corrosion ok, the brake light switch contacts ok. Harness condition looks good, no fraying or signs of damage.
Measuring blocks stable with test contact operating before light switch contact when pressing the brake pedal.
In drive testing I noticed the fault occurs when lifting off the brake. It appears that there may be a relationship between pedal position / electrical switch contact and brake pressure.
some observations when pressing the brake pedal:
Test switch operates at 10.7 Bar.
Brake Light Switch at 15 Bar.
Any chance you have brake pressures (measuring block 009) occurring at the two switching positions?

any additional guidance would be greatly appreciated.