2002 BMW E39 no ECU/DME communication

One shop had this in for an "air con not working" fault and passed it on to us. If I do a full system scan with the Autel Maxisys I get all the modules except the engine ECU. The ABS has a fault for CAN communication with ECU. If I scope the CAN wires at the ECU and ABS module they are identical. The wiring diagram [Autodata] shows diagnostic wires from the ECU (not the CAN wires)going to pins 7 and 9 of the diagnostic plug.
When I connect a breakout box to the diagnostic plug and scope pins 7 and 9 there is a 50% duty cycle 30 ms battery voltage pulse on pin 9. If I try to communicate with the ECU I can see the pulses on pin 7. For now I'm suspecting something is wrong with the ECU.
I've tried to attach an image, haven't done it before on this forum but here goes...

Just hold on while I clean these ECU contacts ....... :ohmy:

The customer pulled the pin on this one. They said the engine light has been on for a long time with no communication and they just want the ac working. I told them I need to scan the ecu to be sure it's not part of the problem and they chose to rather take the car away.