E250 CDI not starting - gearbox communication error?

[Grant Hicks]

Had a gearbox service done by my mobile mechanic about a month back.

It drove fine for a week, then went in and out of limp mode, then wouldn't start.

Had 3 separate diagnostics people out, last one with Xentry, which all showed gearbox communication error.

It also showed starter relay and fuse faulty, but they are all working.

It has been suggested that it may be a SAM unit fault, or a lack of power to the gearbox ECU?

Has anyone had this exact problem and found the solution?

I'm getting drained from all of the guess work and money it's costing.

It's been off the road for over 3 weeks now.

Thanks

 

[mersum1es]

Xentry would have told checklist to narrow the problem...? Gear selector signal (and physical link if you don't have direct selector next on steering wheel), brake light operating signal(s), Circuit 13/30/50/87 tested.

 

[Grant Hicks]

Xentry would have told checklist to narrow the problem...? Gear selector signal (and physical link if you don't have direct selector next on steering wheel), brake light operating signal(s), Circuit 13/30/50/87 tested.

Didn't come up with gear selector problem. It's on the steering wheel. Fitted a new brake light switch, no change. The circuits were tested saying there were faults but there were no faults.
Hence the guy said the SAM unit may be playing up.

All lights on dash come up, just no cranking. No click of starter motor, nothing.