420cdi stuck in gear
12-29-2017, 03:39 PM
#1
Newbie
Thread Starter
420cdi stuck in gear
Hi folks, got a strange one on my GL. Essentially the display says not in park but the stalk makes no effect.
Ive seen lots of problems with either the valve or the controller. So I plugged in my diganostic which is not a C4/5 etc but a semi decent unit and lets me see the transmission ecu and can read live data. It shows me the temperature but also shows me the gear as being in park. I found a document outlining that the ML and GL do not use the shift rod but use an electronic actuator and sensor.
Has anyone had similar problems and any thoughts on the shift actuator and sensor? Im a long way from a dealer and with the vehicle at home and in park (not able to load on a trailer) Id really like a home fix and even prepared to buy a C4 to code the shift module if required. Ive changed many auto boxes and quite competent with electronics but dont want to go down a trial and error operation, mych better to diagnose the fault now.
C
Ive seen lots of problems with either the valve or the controller. So I plugged in my diganostic which is not a C4/5 etc but a semi decent unit and lets me see the transmission ecu and can read live data. It shows me the temperature but also shows me the gear as being in park. I found a document outlining that the ML and GL do not use the shift rod but use an electronic actuator and sensor.
Has anyone had similar problems and any thoughts on the shift actuator and sensor? Im a long way from a dealer and with the vehicle at home and in park (not able to load on a trailer) Id really like a home fix and even prepared to buy a C4 to code the shift module if required. Ive changed many auto boxes and quite competent with electronics but dont want to go down a trial and error operation, mych better to diagnose the fault now.
C
02-07-2018, 03:31 AM
#3
Newbie
Thread Starter
Update, this was the ISM. Bolts onto the side of the transmission to control the gear selection.
If you get a replacement unit, new from merc then it does NOT require SCN coding. You need a C3 etc diagnostics to run the learning function but thats all.
If you get a replacement unit, new from merc then it does NOT require SCN coding. You need a C3 etc diagnostics to run the learning function but thats all.
