400E lost one coil output
 

My 400E came home in limp mode as it was running on only 4 cylinders. What a dog she was! After checking, found that my driver's side coil has no output. First checked coil wire, then back to coil and it has voltage, then on to to voltage triggering with the motor running. OOOps, no triggering as compared to the passenger side coil. Before buying an expensive litle box called a EZL control unit, is there any other way to isolate the cause of the the coil output failure?
I have found an EZL unit (015 545 60 32) at a good price and probably should buy it just to have one handy as they are a 'weak link' on these motors and not always found easily. That's when Murphy's law steps in....can't find it when you need it!

Thanks for any advice given....

Tobias MB
190/5.8 track car

have you inspected the caps and rotors? have they been changed recently? i have seen them when they are neglected to cause the coil(s) to fail, which may take out the EZL, if there isn't triggering i would say the ezl is bad, not sure if you have enough slack in the harness to do so, you may have to remove the EZL to do it, but see if you can reverse the large harness connectors, if you can and the problem moves to the other side then the EZL is definately an issue