Hello everybody, I will appreciate very much your valuable advice on my 1995 E420. About a month ago I got the Check Engine Light after doing the oil change. The engine started to idle erratically up and down when gear selector was in Park or in Neutral position, but when in Drive position the RPM is normal. Drove the car to an MB shop to pull the codes and this are the ones that pull out:
006-ISC / 005-EGR / 004 Secondary Air Injection --> LH1-SF1 /
017 Control Module CC N4/3 / 080 Stop lamp Swicth S9/1 / 096 Starter Lock-out/back-up lamp switch S16/3. While pulling the codes the tech informed me that there were 2 vaccumm lines damage right above the Right Distributor cap and actually, one line was not even there. The tech erase the Check Engine Light and said if the light comes on again come back to shop one more time to pull the codes. Drove the car home and fixed the Vac - Lines, and bingo the RPM was fixed about 95% even on Park and Neutral. The up-down RPM is mild and actually it fixes by itself.
Then, 4 or 5 days later, the Check engine Light is back! Only for a couple of days, then it turned off again and it has not come back in more than 2 weeks.
Now, yesterday drove to the supermarket and when put the gear selector in Reverse it felt that the tranny engage the gears but do not reverse. I inicially thougt that the emergency brake was on, but was not. So, I tried to push a little harder on the accelerator and I got it to move. However it felt like I was pushing a concrete wall. I drove it driving forward.

Sounds like an issue that forum member oldnavy had with his 93 300D....ended up being a part came loose inside the transmission. I'd probably get it checked out ASAP. He said that because he waited, he needed a new transmission, but earlier diagnosis could have prevented that.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Thank you for your feed back. Could it the Neutral Safety Swicth.
Thanks

Dose it happen when hot only?
I had a same problem, when a trans warming up I put in R (reverse) and can few the reverse gear en gate but won't move like a hand break is still on. If I accelerate a little it will move but like locking up forward and reverse at a same time!
I drop the trans and found nothing wrong? only the spring inside K1 accumulator valve are falling apart (the spring separate, the plastic pin dose not hold it together any more). So I bough two new set from dealer about $10 buck each,I replace it for K1 and K2, clean the valve body up put them back together now everything is working find.
Your problem may be different! I would check the oil make sure no coolant in there, or drop the pan, check the valve spring, see if you have the metal chip in the pan, so that you will know something wear out inside... hope it help...cheer
Edit my trans is 722.351xx your may have electronic...cheer

You can look at the linkage and see if it moves properly, but I doubt that is the culprit. The switch just has a little plastic arm that moves along with the shifter, it would not impede proper engagement.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

thank you very much for your feedback.! I will get my wife in the cabin and have her move the stick back and for, while I'm under the car looking at switch! and see what it does! It sounds funny too!
thanks a million, Humberto