I have a VZ HSV Maloo that has an intermittent issue with the "service vehicle soon" light coming up on the dash. It will come on briefly under heavy acceleration or when travelling up hill, on longer steeper hills. The code thrown is U2105, ABS has lost communication with ECM. I have replaced all wheel sensors, had the ABS module checked, installed a new alternator, installed a new battery, checked all the sensor harness' front and back and can not seem to figure out the issue. It's got me stumped! Any ideas?
I think you could be looking in the wrong area. U2105 is an engine fault code, which perhaps helps explain why it comes on under heavy acceleration or travelling uphill. I would have a diagnostic check done on the car to see if you can better home in on the cause of the problem.