[alexs307]

Hello to you all, my friends. My name is Alex, I am 26 years old and this is my first post on this forum.

I have recently become a proud owner if a 320SL ( R129 ), made in 1994, automatic gearbox. The car is in very good shape, but after a complete diagnosis made by a friend of mine, several faults were discovered.

Since I have bought the car ( 1 day ago... ), I noticed a strange behaviour of the automatic gearbox. I tried to count the gears but I can't manage to count more than 3. The gearbox lever shield has written on it P R N D-4 3 2.
Does this gearbox have 5 gears? Or 4? Does it start in 1st or 2nd gear if a slowly press the accelerator? What is the rpm for 4th gear at 100km/h ( 60mph )? My rev indicator shows 3000rpm in 4th gear at 60mph? Does this mean is in 4th gear or 3rd gear? The diagnosis revealed DTC no7, Y3/1Y2 control valve or N15/1.

I read somewhere on this forum that in order to diagnose this fault, I have to take apart the gearbox oilpan. Maybe the wiring is faulty. This is a easy job. But where do I find the valve inside? Is it possible to repair it and if affirmative, how? Does any of you, my friends, have photos of this valve's location?

Sorry for the ammount of questions but there are a lot of new things for me, starting with the engine ( I used to drive a 1988 300hp Opel Kadett Turbo so far) and continuing with the automatic gearbox.

Thanks in advance!

 

[RKH]

Based on your P R N D-4 3 2 pattern, you have a 5-sp transmission.
At 60-mph 3,000 RPM seems high, that indicates you are not in 5th gear.
I am assuming you are putting the shift lever at 'D' and not at '4' when you drive.

 

[alexs307]

So the gearbox has 5 gears...ok...

The shift lever is at D when I drive. 3000rpm at 60mph means 3rd gear or 4th gear?

Another question: do you know what other Mercedes automatic gearbox use the same Y3/1Y2 valve? As Mercedes parts are difficult to find in Romania, maybe I can find the right part on a second hand box, coming from another car. There are a few chances to find exactly a broken SL.

 

[alexs307]

If the car is going at 80mph,let's say, with gearbox lever in "D", if I move it to the left, meaning "4", should something happen? Because if I switch it after in "3", I feel the gearbox downshifting, same thing if i move it in "2".

What about Y3/1Y2 error? Can someone help me with a guide to diagnose the faulty valve or wiring? I am afraid to take apart the oilpan as I don't know what can I find inside. Where is that valve located?

Any other opinion on 60mph at 3000revs? Is it 4th gear? 3rd gear? Does this car have 4 or 5 gears?

 

[bobterry99]

If the car is going at 80mph,let's say, with gearbox lever in "D", if I move it to the left, meaning "4", should something happen?

Yes. The transmision should downshift from 5th gear to 4th.

What about Y3/1Y2 error? Can someone help me with a guide to diagnose the faulty valve or wiring?

This solenoid is wired between sockets #1 and #10 of the main electrical connector to the transmission ECU. The electrical resistance of the solenoid should measure between 4 and 8 ohms. The output voltage between #1 and #10 should be around zero volts DC an idle and around 5 volts DC with engine RPMs > 1000. Of course, you have to have the connector plugged-in to the module when you measure the voltage, and that could be tricky.

Any other opinion on 60mph at 3000revs? Is it 4th gear? 3rd gear? Does this car have 4 or 5 gears?

Without question your car is in 4th gear at 60 MPH, though it should be in 5th.

 

[alimurat]

your problem is about selonoid valve part number y3/1y2(124 304 04 90 ) and HGS=EGS ünit. hgs=egs is in ecu box. selenoid valve is under the oil fitter in transmission gearbox. you can see it after put out the oil filter box. there are two wire on it. you have to remove them. selenoid valve has to be cold when you measure the ohm and it has to be nearly 7 ohm.as you ac 12V use to charge ,"dıııırt" if vibration occurs it means your prob is not about it. after it delete codes and check the wires and hgs=egs units.

http://www.benzworld.org/forums/r129-sl-class/1402982-91-300sl-shift-problem-no-4th.html

 

[alexs307]

Thanks a lot, Bobterry and Alimurat. I will check tomorrow the tricky valve, I will take apart the oil pan and see if the wires are ok, then I will charge the valve at 12v to see if it vibrates...your indications help me a lot, bobterry, as i wasn't able to find the EGS pinout anywhere on the net.

Be right back after diagnosing this fault.