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Discussion Starter #1 (Edited by Moderator)
Hi I am reluctant to post this just yet as I have not finished checking all the components but if someone out there has already had this fault it would cut out a lot of work.
I have a 1997 R170 230SLK with the Vario roof which will not open. As Live in Scotland where it has rained in some shape or form almost every day for about a month it migh not seem like a big issue but it is on of the best features of the car :)
When I unlock the car and get in there is a noise from the rear of the car which sounds like the roof hydraulic pump operating for a short time on operating the switch the red light flashes but nothing happens.
If I push the switch to the closed position I hear the pump operate and can see the roof push slightly more closed.
Also neither of the rear windows will go down even with the window switches.
I have checked all of the micro switches, I think, and all seem to be operating properly and intend to check them at the pins on the MFCU over the next few days but given the additional issue with the rear windows I suspect the MFCU might be faulty.
Any advice or suggestions, that dont involve a Mercedes dealer, would be appreciated.
 

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Premium Member 2005 SLK55 AMG; 2005 SLK350
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The sound you hear briefly when you first turn the key is likely the fuel pump - confirm with your ear against the open filler tube.

Did you check the fuses?
 

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Discussion Starter #3
Thanks for that I( will check the fuel pump. Yes I have checked all the fuses with a multi meter and all are good. I assume there is power getting to the pump as it operates in closing mode
 

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Premium Member 2001 SLK200K/2001 SLK320
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I have a 1997 R170 230SLK with the Vario roof which will not open.

<snip>

If I push the switch to the closed position I hear the pump operate and can see the roof push slightly more closed.
Also neither of the rear windows will go down even with the window switches.
How long have you had this car?

The rear windows only go down and up again with the roof .. technically that's not entirely accurate but good enough for now.
 

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Discussion Starter #5
Hi only had the car a few days but I believe that the windows should go down with the window switch if it is pressed twice,
If the roof switch is operated then the front windows drop a little and the rear window open completely is this not the case?
 

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Premium Member 2001 SLK200K/2001 SLK320
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Hi only had the car a few days but I believe that the windows should go down with the window switch if it is pressed twice
That'd be nice but that's an R171 feature, you have an R170

If the roof switch is operated then the front windows drop a little and the rear window open completely is this not the case?
Front windows retract fully, bootlid starts to open, rear windows retract fully, bootlid continues to open, roof unlatches and does its thing and folds into boot, bootlid closes, cycle complete. .. choice to continue holding switch at this stage .. <pause> .. front windows come up again. Rears windows stay retracted.

You have pulled the luggage cover in the boot into place havn't you? The thing that looks like a roller blind?
 

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Discussion Starter #7
Hi thanks for clarifying that I have looked at so many diferent diagnosis flow charts that they must have got mixed up in my head.
As for the the luggage cover switch as far as I can see it is working as it should. I have checked the continuity open and closed and it is working as a switch on and off.
When the roof opening switch is operated there is nothing happening. The front windows do not retract the only thing that happens is the switch light flashes on and off.
If I operatate the window switches the front windows go up and down as they should, but the rear windows don't do anything no matter how many times the button is pressed is that how it should be?
There does feel like 2 positions on the switch when depressed.
Regards
Goges
 

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Registered 2002 SLK320
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Hi,

Forget opening rear windows, IT IS NOT AN R170 Feature !!

The sequence is as described above and REAR WINDOWS ONLY OPEN IN CONJUNCTION WITH ROOF OPERATION :wink:

HTH,

Cheers Dave
 

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Premium Member 2005 SLK55 AMG; 2005 SLK350
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Discussion Starter #11
Hi I carried out the sanity check and measured the resistance at the MFCU pins using a digital multimeter on 2K setting.

Pin 28 test light lit on switch operation 0.089 ohms
Pin 29 test light lit on switch operation 0.046 - 0.105 ohms as pump operated
Pin 30 test light lit 0.046 ohms
Pin 32 test light lit 0.040 ohms
Pin 33 test ligh off but lit when switch moved
Pin 37 test light lit 0.374 ohms
Pin 52 test light of but lit when switch moved
Pin 54 test light lit 0.038 ohms
Pin 69 test light lit 0.546 ohms

As far as a I can see the microswitches operated as required. I removed the MFCU and there was a little corrosion Verde Gris) at terminals 4, 5, 22, 23, 24, 43, 44, 74, 75, 76, 77 and 78 iwhich cleaned off well I opened the MFCU to inspect and it appeared clean and corrosion free on replacing it and operating the red switch to lower the roof the front windows dropped once but I couldnot get it to replicate this and they had to be put back up with the window switches.
The only other change is that the LIM light is now lit and will not go off.
Any ideas suggestions greatly appreciated
 

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Premium Member 2005 SLK55 AMG; 2005 SLK350
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It does appear that your switches are correct for a fully closed roof. I think you should resolve the LIM light and any other warning lights first. Are all your warning lights working? They should all illuminate at least briefly when you first turn the key.

At this point, if I were you, I'd look for a good MB- or SLK-specific scanner. If you suspect a bad connection at the MFCU this would help rule it out.
 

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Discussion Starter #13
Hi just a quick update as to where I have got so far.
Having removed almost every trim panel involving the roof checked wiring and switches and managed to confirm tha the rear windows both operate as they should when fed power direct I decided to take the car to a local Auto Electrician to have the codes read.

After checking the codes he cam back to tell me that there had been 18 fault codes recorded. Not probably a record but a pretty good effort. Some of them probably caused by me with all the hamfisted dicking about.

On clearing the codes the following ones immediately returned
ETC-Electronic transmission control
1.1. 24 The right front wheel speed of the traction system is implausible
1.2. 120 The right fron wheel speed of the traction system is sporadically implausible

ABS
2.1. C1101-016 L6/2 Right front speed sensor open circuit in wiring
2.2. C1101-008 L6/2 Right front speed sensor
2.3. C1101-007 L6/2 Right front speed sensor
2.4. 1200 S9/1 Stop lamp switch Plausiilty

CCM-Multifunction control module
3.1. B1268 Please refer to vehicle service manual

RFL-Radio Frequency Locking/electric central locking
4.1. B1000 N54/3 Radio Drive Authorisation system

VR- Vario Roof
5.1. Speed sensor status symbol is invalid

TAC Automatic Temperature control
6.1. B1416 A31ml coolant circulation pump

Now I'm sure some of you eagle eyed readers have spotted a recurring theme about the right front speed sensor, but first, in my defence.,I have to point out that the reason I did not follow up the ABS light being on was because some-one thought it a better plan to remove the bulb from the warning light rather that fix the problem!! (until a couple of years ago the UK MOT test had it that if the light didn't illuminate then it could't be checked and couldn't be failed)
My plan is to check the wiring or replace the sensor at the right front wheel, replace the stop lamp switch cozz they are cheap and easy to do initially and hopefully its not the ABS Pump/module. Any thoughts suggestions or advice would be appreciated
 

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Hi just a quick update as to where I have got so far.
Having removed almost every trim panel involving the roof checked wiring and switches and managed to confirm tha the rear windows both operate as they should when fed power direct I decided to take the car to a local Auto Electrician to have the codes read.

After checking the codes he cam back to tell me that there had been 18 fault codes recorded. Not probably a record but a pretty good effort. Some of them probably caused by me with all the hamfisted dicking about.

On clearing the codes the following ones immediately returned
ETC-Electronic transmission control
1.1. 24 The right front wheel speed of the traction system is implausible
1.2. 120 The right fron wheel speed of the traction system is sporadically implausible

ABS
2.1. C1101-016 L6/2 Right front speed sensor open circuit in wiring
2.2. C1101-008 L6/2 Right front speed sensor
2.3. C1101-007 L6/2 Right front speed sensor
2.4. 1200 S9/1 Stop lamp switch Plausiilty

CCM-Multifunction control module
3.1. B1268 Please refer to vehicle service manual

RFL-Radio Frequency Locking/electric central locking
4.1. B1000 N54/3 Radio Drive Authorisation system

VR- Vario Roof
5.1. Speed sensor status symbol is invalid

TAC Automatic Temperature control
6.1. B1416 A31ml coolant circulation pump

Now I'm sure some of you eagle eyed readers have spotted a recurring theme about the right front speed sensor, but first, in my defence.,I have to point out that the reason I did not follow up the ABS light being on was because some-one thought it a better plan to remove the bulb from the warning light rather that fix the problem!! (until a couple of years ago the UK MOT test had it that if the light didn't illuminate then it could't be checked and couldn't be failed)
My plan is to check the wiring or replace the sensor at the right front wheel, replace the stop lamp switch cozz they are cheap and easy to do initially and hopefully its not the ABS Pump/module. Any thoughts suggestions or advice would be appreciated




I think that you have a good plan there :smile: I am thinking that it is the sensor that is causing the problem with the roof not opening? as that was a recent problem with my R170 but in my case it was the OSR Sensor.

Good luck
 

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Premium Member 2001 SLK200K/2001 SLK320
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Any faulty wheel speed sensors will cause the roof to not work. It's an inbuilt safety feature that the roof does not operate above 7mph (I think). A broken wheel speed sensor or wss wire will return an implausible speed (e.g. 32000+ rpm). Hence car doesn't know what it's doing and the safety feature (roof no worky) comes into play. Same or similar applies for yaw rate and lateral acceleration sensors. Anything faulty on that system it seems, can and will also bring up the ABS BAS/ESP lights..
R170s really are not that advanced that they can differentiate so you'll find that one fault can throw up a whole mess of issues ..

There's just too much focus on the roof at times ..
 

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Discussion Starter #16
Thought I would give an update about the roof problem which seems to be turning into my lifes work.
Having identified the right front wheel speed sensor and the brake light switch as a possibles fault I removed the sensor and the brake light switch.
I reconnected the battery and just out of curiosity tried the roof switch.
The windows all went down and the boot (trunk) opened as it should but that was as far as it got.
On pressing the roof switch to close the roof all went well with the boot locking in position and the windows closing except for the left hand front window which stopped a couple of inches short of closed the windows would not open or close even when using the window switches.
I have now replaced the wheel speed sensor and brake light switch but the ABS light is staying on, unless any one knows of a way to turn the light off? I may have to pay another £45 to clear the fault codes.
Unfortunately the roof still does not work. Although on trying it on one occasion the windows dropped but still do not work using the window switches on the positive side it is a nice sunny day. :)
I appreciate that ABS light may be affecting the roof and I will need to clear the fault codes but given the random nature of what's happening It feels like possible a wiring issue or a fault with the multi function control unit.
Anybody got any suggestion that don't include a box of matches and a gallon of petrol please help.
 

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Premium Member 2001 SLK200K/2001 SLK320
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The windows all went down and the boot (trunk) opened as it should but that was as far as it got.
Could be a case of the roof not being opened for so long that the hinges and seals are bone dry along and it's just stuck

I have now replaced the wheel speed sensor and brake light switch but the ABS light is staying on, unless any one knows of a way to turn the light off? I may have to pay another £45 to clear the fault codes.
Centre steering wheel. Spin it all the way to the left and then all the way to the right, return to centre. Best done whilst stationary ;)
 

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Premium Member 2005 SLK55 AMG; 2005 SLK350
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OK - so it sounds like you have made some progress?

I would still recommend you address all other faults before investigating the roof. The fact the roof is moving now is encouraging, and you might be able to proceed, but better to eliminate them first.

It's crazy to keep taking your car in for a scan - buy your own.

You will next need to open the roof until it freezes, and then re-scan. Or just leave the key on and measure the switches again.
 

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I have now replaced the wheel speed sensor and brake light switch but the ABS light is staying on, unless any one knows of a way to turn the light off? I may have to pay another £45 to clear the fault codes.
Have you driven the car since replacing the sensor and brake light switch?

When I did mine the fault (warning light reset itself) cleared within 10 seconds of driving.

Good luck
 

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Discussion Starter #20
I dont think that the roof is sticking on the rubbers as I have opened it manually more than once.
I tried turning steering lock to lock as suggested by m4rCu5 with no success
I took the car for a drive after fitting the sensor but light stayed on.

The situation is as follows
Roof does not move or any sound from pump etc when switch operated in either direction.
The operating switch flashes slowly when put in either up or down position.
Front windows are stuck in the down position nothing happens when the window switches are operated.
Is there a micro switch in the roof operation that controls the windows?

I noticed a fair amount of flakey corroded metal around the back plate when fitting the sensor I cleaned the area as best I could but there is a possibility that some of the crap stuck to the magnetic end of the sensor so I will remove it and check again.
 
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