2005 ML 350 (163.157), with 112K miles, presents with ABS, BAS and ETS/ESP illuminated warning lights in IC.

SDS quick test reveals a fault code for the left front wheel speed sensor. With the vehicle in Park, the data stream for that wheel shows a rapidly fluctuating vehicle speed of between 7-12 MPH, occasionally but briefly falling to 0 MPH. The data stream for the other wheel speed sensors show a vehicle speed of 0 MPH.

The ABS, BAS and ETS/ESP warning lights remain illuminated with the original left front wheel speed sensor disconnected; lights also remain illuminated following the installation of a new M-B wheel speed sensor.

The MY 2005 163 integrated the ABS and ETS control units into one unit on the front of the ABS pump. A quick look at the wiring diagram reveals the left front wheel speed sensor feeding directly to the control unit, which would suggest a faulty control unit. The control unit's wiring harness plug connector is intact and free of corrosion. The left front wheel speed sensor wire is intact and defect free.

And, on a possibly related note... the vehicle was involved in a frontal impact accident approx. 4 weeks ago; the front bumper clip was damaged but the ABS/ETS control unit itself was not impacted. The warning lights appeared shortly after the accident.

Just a coincidental failure of this control unit?

Or a control unit fault precipitated by the shock of impact? (The ABS pump/control unit assembly is mounted on the most forward lateral aspect of the left front frame rail, to the left of the radiator.)

Thanks.