![]() |
|
|
|
#1
|
|||
|
|||
1990 129 no 5th shift
Probably should have put this here rather then SL thread, sorry.
I have a '90 129 that won't shift into 5th gear. I took it to Mercedes and had it checked out and they spent a number of hours on it and came up with a bad HSG mod. Because I have a repair shop and we're over 2 hours away from the dealer I ordered and installed new HSG with no change. This problem has been going on for a few years now so we reinstalled the original HSG and found a code 9, road tested the car with this controler and there was a 3-5 shift skipping 4th. While we working on this car in the past, when the new HGS controler was installed we found a bad connection on the trans overload protection switch so I figured the old controler still had that code in it so I cleared the codes in all the mods and road tested. Back to square one, no 5th gear and no codes in any of the mods. I don't understand why it doesn't set a code when it's not shifting into 5th, Anyone have any ideas? Thanks, Ron |
#2
|
||||
|
||||
What else was changed, done to solve this problem? Do you no 5th or no 4th
|
#3
|
|||
|
|||
Nothing has been replaced other then the HGS mod. I dropped the pan and cleaned the sol. but didn't really find anything there. Repaired a connection on the trans overload switch. Checked the over voltage relay, this one has a fuse in it and it has never been blown. Checked the function of the switch on the shifter and that is working properly.
I made a pulse tester and that is what I'm using to get the codes. I can access the MAS, EZL both of which have a list of codes in alldata but I couldn't find a list on the HGS mod. I used pin 14 for the MAS, 8 I think for the EZL and 13 for the HGS. The code 9 I pulled from the HGS I thought was the trans overload switch but I'm not sure of that because I couldn't find an actual list for the HGS. Not that long ago when driving the car with the new HGS installed the car shifted perfectly for about 50 miles so this leeds me to believe that it is a wiring/connection issue rather then a transmission fault. I've checked the vac lines and found no problems. My understanding of the system is that the controler looks for load, RPM's and the position of the shifter switch. All things being right it is suppose to shift into 5th. |
#4
|
||||
|
||||
I never knew the 90 SL had a 5th gear. My 95 only has 4.
![]()
__________________
95 SL500 Smoke Silver, Parchment 64K 07 E350 4matic Station Wagon White 34K 02 E320 4Matic Silver/grey 80K 05 F150 Silver 44K |
#5
|
|||
|
|||
5 sp auto tranny mod year 1990? or 95?
I thought the 5 speed (electronic shifting) debuted in model year 1995 on the R-129 series
|
#6
|
||||
|
||||
Quote:
![]() ![]() ![]()
__________________
95 SL500 Smoke Silver, Parchment 64K 07 E350 4matic Station Wagon White 34K 02 E320 4Matic Silver/grey 80K 05 F150 Silver 44K |
#7
|
||||
|
||||
Code #9 in the HGS is the valve block control valve (Y3/1y2) in the valve body Verify that the alternator is not under or over changing. Check the alternator
Output at the battery post with all accessories on including the engine running, lights, heater, etc. 13.4 to 14 volts =s ok. If the volts are less than 13.1 the charging systems is marginal, then do a voltage drop test, the reading should be 0.00 to 0.10which means the ground is ok. If more volts are present you have a bad battery ground. Check and clean the ground wires W1 main ground behind the instrument cluster, W16/2 and W16 on the firewall. Clean the connector contacts on the throttle potentiometer (TPS) Clear the code, then drive the car at about 56MPH in position 4 release the gas pedal and immediately move the lever into the D position, the transmission should shift in to 5th. Then select 4 the transmission should down shift to 4th gear. Check for codes Lets verify we have no 5th gear. At 62MPH with a 3.69 rear 3 = 4300rpm, 4 = 3000rpm, D/ 5th =2200rpms. With a 3.46 rear 3 =4000 4 = 2800 and 5 = 2100rpms. Make sure you have the right HGS for that model car. The 722.5 was an option. |
#8
|
|||
|
|||
We've checked all the grounds, voltage drop, does not go into 5th, charging system, new HGS from Mercedes using the VIN to order and there is no info in alldata as to the values coming into and leaving the mods. Is it possible that something is causing the controlers to fail when plugged in?
With everything we've checked it should shift into 5th but we're missing something. Anyone have a telephone number they want to give up so we can pick your brains in real time ![]() |
#9
|
||||
|
||||
Is it possible that something is causing the controlers to fail when plugged in?
The Over Voltage Protection relay should protect the controllers. You should always disconnect the battery and discharge any static electricity by grounding yourself before disconnecting/connecting any controller. I should have ask this question before, did the transmission ever shift into 5th gear. If the transmission fluid and pan are clean, no internal problem; then I would change the control valve for 5th gear (Y3/1y3) and the throttle valve switch (S29/4) even with no code these sensors can fail mechanically. The HGS did have an Y3/1Y3 code The TCM / HGS receives the following electrical signals Voltage supply, over voltage protection relay powers the TCM (HGS) Engine speed; EZL / AKR control unit, TN signal Load input: EZL/ AKR control unit. Manifold vacuum and DI control module Throttle position: Throttle position switch: S29/4 Vehicle speed; Out put shaft on Trans/ speedometer. Digital and mechanical Speedo/ wheel sensor. D contact switch: Shift lever in D position Control valve: Valve body, pulse modulated Email me or post your fax number and I will send you the diagnostic pin chart to diagnose the complete systems, plus fault codes for the MAS, EZL/AKR and the HGS. If you have any question email a contact number and I will call you back ![]() mastertech@mastertechtrans.com shop 928euro@mastertechtrans.com home |
#10
|
|||
|
|||
Quote:
I have the same problem with my w124 E320 1994 If you can pls send It to my email anas2912@hotmail.com |
#11
|
|||
|
|||
Hi
Can you please e-mail the diagnostic pin chart , I have a problem with my 300SL 1992 . Only first and the second gear works , won't shift into 3-4 or 5th gear and the speedometer doesn't work . Thank you . Peter pkurek@cfl.rr.com |
![]() |
Bookmarks |
|
|