I own a 2006 Volvo XC70 Cross Country AWD Estate fitted with a 2.4-litre 185bhp 5-cylinder diesel engine. It has just completed 100,000 miles. During a trip last week a yellow warning triangle appeared on the dashboard accompanied by an 'Anti-Skid Service Required' message on the vehicle information console. The car continued to drive normally and there appeared to be no change in its braking performance. The following day I took it to my local Volvo franchised dealer who examined it and diagnosed a fault with the Differential Electronic Module (DEM) which, as I understand it, is an electronic unit attached to the differential on the rear wheel drive assembly.

The engineer had checked all the contacts and indicated that the fault was not with any of these but that it was a problem internal to the DEM module itself. Then came the bombshell. The quoted cost of replacing the faulty DEM with a new unit was over £1700. But can the DEM unit be repaired? The 'Anti-Skid Service Required' message comes up every time the car is started but this is not accompanied by the ABS warning light or any other ABS related message.