Recently acquired another 05 SLK350 with 124k miles and assorted problems for a bargain price. Most of the problems are simply maintenance related (motor mounts, Intake flap control lever, cam position sensor, seat belt buckle open circuit) but there's one problem I cannot get my head around. The check engine light will not light when I turn on the ignition, nor when there are codes present. I need to have the CEL functioning in order to pass the smog test and register the car in California. In conjunction with the CEL, the Reset and it's + and - buttons are dead, and the tachometer is dead. I found the ribbon connector for the reset, + and - detached so I reattached it but it made no difference. Except for those 3 areas, the other cluster functions are okay. I ran diagnostics using an icarsoft and understand the codes related to various problem areas, but none of the codes relate to the cluster issues. The only link I see among the CEL, Tach, and everything the Reset covers, is that all involve interaction with the ECU. I think the problems are within either the cluster or the ECU, but again, there are no diagnostics to indicate they are not communicating with each other. I believe the CEL may be an LED so a burned out bulb is not likely. Now it's time to reach out to the community to ask if anyone has had a similar experience, sees anything wrong with my thinking, knows a common connection link shared by the CEL, Tach, and Reset, or .....? Thanks for reading and let me know what you think.

 

Send an email to a these guys: https://www.commandonline.co.uk I'd be really surprised if these guys can't help you.