The BMW technician has diagnosed the replacement of the DME/DDE unit. The fault with the engine control unit (DME) is that there is a communication fault with the CAN bus network that sends signals between the vehicles control units. All the wiring has been tested and he found the fault to be the DME outputting the wrong voltage down the high and low CAN bus wires causing the warning lights and the gear selector lock fault.The price of replacement £1100.00. Is there a cheaper alternative to this? I just can't afford this.