All the manuals including Bentley and Audi Support indicate this ground connection is in Instrument Panel Wiring harness. Contrary to similar schematic splices that are clearly identified, the Bentley wiring diagrams do not show a ground splice but simply refer to it as Ground Connection 269. We physically located "269" and it is a 2 thick and 4 thin Brown w/ white stripe 6 wire splice in the harness for cluster connections branch of main wire harness on right side of steering column inside dash.
We know of 6 grounds attached to Ground Connection 269, they are Coolant Temp Sensor G2, Fuel Sender G, Coolant Level Low Sensor, Dash Light Dimmer Control, WW Low Level Sensor and Cluster Ground. All these devices currently have an intermittent ground on this vehicle.
We have entire dash including steel cross bar removed and are trying to find the physical Chassis Ground for 269 splice. We measure no continuity from 269 to chassis. We are still unable to find this chassis ground connection point. Is the 269 splice chassis ground switched on by ign inside the Cluster? Can anyone offer more insight?
Yes we just determined that the 269 ground is switched thru ignition and that it appears the cluster is bad as even with ign on, there is no measured chassis ground for 269.
We installed a temporary ground wire to the 269 ground connection and all sensors on that ground circuit work again. We are going to try running with this until cluster needs to be replaced for possible other internal failures... thoughts?
A note to Bentley Publishers about MKI TT Wiring Diagrams, please update schematics with a simple note indicating Ground Connection 269 is chassis grounded thru Cluster only when Ignition is on. This would have saved about 10 hours labor and the client's money would have been better spent on a replacement Cluster due to the ign switched 269 internal grounding failure!