[BSY]

You mean this cable? See attachment.

Sorry not that. I thought it was a cable. Its a rod.

Thats a pic from ebay. I hope I dont get into grief when trying to remove that later.

 

[Sneaky Pete]

That rod? As @Dave2302 said,you will to get under the car. See attachment.
First note in the list of actions is ofcourse very encouraging...... 😁

 

[Turbo]

What's that leaver for? Is that the one that selects the gear? If so, then what's all the cables attached to the "thing" for? I thought THAT (electrical cables) was the gear selection.. ?

 

[Sneaky Pete]

What's that leaver for? Is that the one that selects the gear? If so, then what's all the cables attached to the "thing" for? I thought THAT (electrical cables) was the gear selection.. ?

Afaik it does not select the gear,it is the gear RANGE slector. So P,N,D,R. Within the range (at least in D) gear is selected electrically,either automatic or by hand with the stick or the paddles.
At least that is how I think it works. But I've been proven wrong before........ 😁

 

[Dave2302]

Danger! Risk of death caused by vehicle slipping or toppling off of the lifting platform

I thought THAT (electrical cables) was the gear selection.. ?

Keep Up ...............
We discussed this early on, ISM / Shifter / 7G / 5G etc .................

Kind of fly (shift) by wire on a later 7 G Tronic, 722.9 but this car has 722.6 5G (5 speed Auto) so none of that malarky.................

The 5 Speed and Early 7G Rod selects Parking Latch and moves the "Manual Valve" on the Valve Block between P R N and D, which controls the way the Transmission then behaves, yes Pete, the Range !!.

Later 7G's without a "Shifter", they have a column stalk to shift P R N and D and Paddles for manual ......... They also have the ISM on the side of the Gearbox, which is a module in it's own right, that has a Servo Motor which moves the 7G's Park Latch and the Manual (Range) Valve, the ISM is also part of the Theft relevant Immo System. It receives CAN data from the Shift Stalk, (and a bunch of other stuff for the Immo)

There y'all go now ya know how it works 🤣

 

[Dave2302]

LOL @Sneaky Pete you just beat me to it

 

[Dave2302]

I hope I dont get into grief when trying to remove that later.

Simple spring clip and then just push the Rods pivot outta the bush on the Shifter ...............

Whatever you do do not try and undo the Allen (Torx?) Grub Screw, that clamps the rod in the correctly adjusted position, if you undo that you will have more grief needing to set the adjustment back up spot on

 

[BaD_81]

I am a bit confused, it said Historic event for the shifting mechanism, why is it important now?
Is there active one?

 

[Dave2302]

All Codes will say historic if it isn't a permanent fault i.e. not there as you read it upon Ign On, much less details on the OBD Readers .........................

This fault is intermittent, but of course becoming more frequent as they usually do

SDS has Event Log, giving frequency of fault, exact mileage etc etc, so the operator who knows his onions will look at that as well as read the codes, I'm pretty sure that iCs like many others just knows yes it's there now, or no it isn't

 

[BSY]

Simple spring clip and then just push the Rods pivot outta the bush on the Shifter ...............

Whatever you do do not try and undo the Allen (Torx?) Grub Screw, that clamps the rod in the correctly adjusted position, if you undo that you will have more grief needing to set the adjustment back up spot on

Thanks Dave! Working under the car is a no go for me. I still want to see my children grow up.

 

[BSY]

That rod? As @Dave2302 said,you will to get under the car. See attachment.
First note in the list of actions is ofcourse very encouraging...... 😁

Thanks Pete! Very he,pful. But I dont need to remove the rod from the tranny, just remove the rod from the shifter. Hopefully I wont need to get under the car.

 

[Sneaky Pete]

Thanks Pete! Very he,pful. But I dont need to remove the rod from the tranny, just remove the rod from the shifter. Hopefully I wont need to get under the car.

Yes I understand. But could be that the rod has a threaded end and is screwed in at the part attached to the shifter. So you would have to remove it like tirning out a screw. No idea, never done it. Don't know how it is attached to the shifter. Just guessing here. Maybe @Dave2302 knows. But I guess you will find out. 😁

 

[Windinmyhair]

Thanks Pete! Very he,pful. But I dont need to remove the rod from the tranny, just remove the rod from the shifter. Hopefully I wont need to get under the car.

Ummm, if you remove the rod from the shifter won’t you be undoing the grub screw of doom that @Dave2302 mentioned above?

 

[Sneaky Pete]

Ummm, if you remove the rod from the shifter won’t you be undoing the grub screw of doom that @Dave2302 mentioned above?

Ahh yes,you are right, I missed the post from Dave. He already explained how to remove the rod from the shifter. But because the MB instructions explicitly tells you to first detach the rod from the lever at the transmission I think you will not be able to remove it from the shifter without doing that. But I leave it to @Dave2302 to confirm or deny that. He's the expert here.

 

[BSY]

Update. I was able to remove the circuit board without removing the shifter rod. (Both ends).

The shifter is still in the car. Note that the housing of the shifter is both GLUED and screwed together. I had to pry the housing off while that rod was still attached. I am not a mechanic. That giant e clip will be a challenge for me to remove as I don’t have the right tool. AND it will probably fly away and fall into oblivion if I do succeed to pry it loose, I have the circuit board in my hands now. Now its in my territory. Haha. I will find that little devil soon.

 

[Alex 3]

Hi Mates!
Recently my baby didnt want to change gears. Stuck at 2nd or 3rd. Pulled over and restarted the car. All ok again. Shifting was rather smooth as usual. But I know it will be back again. I quickly researched here for answers. Everyone pointed to conductor plate, speed sensors as the usual suspect. I connected good old iCarsoft and diagnosed. There are 2 speed sensors Inside the tranny. Yn/6n2 and Yn/6n3. I drove around and recorded the rpm. Sure enough there are times that 6n3 reported 0 rpm when 6n2 reported a plausible one.
View attachment 608770
Most resources I saw on the page deals with the 7G tranny. Mine is a 5 speed. I hope I don’t bother you guys too much with The following questions.
1. Are the speed sensors in the 5G tranny as problematic as the ones in the 7G version? I cannot see anyone selling speed sensors for 5G tranny. Only 7G. At least not in ebay.
2. What is the reason for having 2 sensors? Redundancy?
3. i see a lot of people selling conductor plates WITHOUT the TCU and solenoids. Any opinion in these?
4. I would rather just replace the speed sensor and maybe the solenoids, I dont want to mess with the TCU. Is that possible?

thanks a million guys.

Bryan

View attachment 608771 Pla

Hi Mates!
Recently my baby didnt want to change gears. Stuck at 2nd or 3rd. Pulled over and restarted the car. All ok again. Shifting was rather smooth as usual. But I know it will be back again. I quickly researched here for answers. Everyone pointed to conductor plate, speed sensors as the usual suspect. I connected good old iCarsoft and diagnosed. There are 2 speed sensors Inside the tranny. Yn/6n2 and Yn/6n3. I drove around and recorded the rpm. Sure enough there are times that 6n3 reported 0 rpm when 6n2 reported a plausible one.
View attachment 608770
Most resources I saw on the page deals with the 7G tranny. Mine is a 5 speed. I hope I don’t bother you guys too much with The following questions.
1. Are the speed sensors in the 5G tranny as problematic as the ones in the 7G version? I cannot see anyone selling speed sensors for 5G tranny. Only 7G. At least not in ebay.
2. What is the reason for having 2 sensors? Redundancy?
3. i see a lot of people selling conductor plates WITHOUT the TCU and solenoids. Any opinion in these?
4. I would rather just replace the speed sensor and maybe the solenoids, I dont want to mess with the TCU. Is that possible?

thanks a million guys.

Bryan

View attachment 608771 Pla

I got nothing to add re conductor plates but I am envious of the fact that you have the 5G vs the 7G.
I have had a number of cars including E class, C class and of course the two SLK320 R170s with the 5G and for my money it is a smoother more predictable transmission.
Arguably on downshift 2-1 is a bit steep but that is much preferable to the lack of engine braking on the 7-6 and 6-5 of the 7G. I just blow by them. Good luck sorting out your issues.

 

[Alex 3]

So did I but OP insists it's a 5 speed the Data Card and Myk's table says it is 5 speed too

The 7G did not come into the R171 until 2004 MY in the SLK 350 if my info is correct. The 280 got it in 2005.
Interestingly the 7G was also sold to Nissan for the 2014-2019 Infinity Q series.

 

[BSY]

Ok so when I first opened the board I was amazed at the engineering and design! Top notch, highest quality! The board was immaculate. I couldn’t find anything wrong with it. The optos were clean as a whistle. Given that optos are no contact switches, it should be extremely reliable. I tried for 30mins to find the fault. I used a high power magnifying glass. I was losing hope. I wiggled the optos around then the devil finally showed its face. Indeed it was as what most people say. The solder at the optogates base had cracks. they are not easy to find.

they only showed when you wiggle the optogates. So this is a quick solder and re-assembly and hopefully my baby will be ok again. So here are my thoughts. 1. how did this happen? The optos are contact free. They should last a lifetime. 2. Can other components have similar problems In the future? This board is extremely well made. I really dont have the answer but my opinion is: 1. the solder used here looks like the lead free type. They suck. They are brittle and have a higher melting point. Perhaps back in 2005 they were still learning how to use this properly. 2. The optos seem to have expansion issues. Meaning during manufacturing the solder hardened first before the component was able to cool and shrink. This leads to stress on the solder joints. Over all I do not see this problem however affecting other components. there is a reed relay on the circuit though, I am unsure what its for but thats a mechanical device and can fail. But then again reed relays, compared to regular relays are extremely more reliable. I can understand why they glued the shifter housing shut (not the black circuit board housing, thats only held by very small allen screws). They were so confident nothings gonna go wrong.
the electrolytic capacitors seem fine. Unlike the ones in the ECU, these are nit subject to heat and should last. Ok thats that. I will update once I’ve fixed it. Cheers mates.

 

[BSY]

@admins maybe we can rename this thread to “5G Shifter circuit board repair” or something to that effect. The problem and hopeful solution has nothing to do with conductor plates. I’ve searched this forum and I don’t see much about the circuit board repair topic, especially not for 5G tranny.

 

[BSY]

@BSY please slow down.
I am not 100% sure but these readings are correct in P and or N, selecting D or R you have the other speed sensor reading the RPMS. I could be wrong
@Dave2302 how incorrect my memories are mate?
Take a look at this and check component location/description. Just to be on the safe side

https://ryououki.no-ip.com/r170/

Fyi. The readings were taken when the car was moving, albeit very slowly. 5Km/h i suppose. I was in the carpark.