Topic: Trans indicator

[Oliver GER]

Hello,
I'm new her and also new owner from a 91 Cheiftrain 6.2 Diesel. I bougth the rig very cheap her in Germany.
It runs and shift great but on thing makes me nervous: On the dashboard some is a yellow Trans indicator what dos this mean?
I didn't found a owner's manual jet. Is her someone who can help me out?

regads
Oliver from Germany

[tmsnyder]

According to this manual for the p30:


https://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf


on page 8-6 they started putting the 4L80E electronically shifted transmission into motorhomes in 1991.   Easiest way to identify this is by looking at the bottom pan on the transmission and counting the bolts and looking at the shape of the pan.   Google 4l80e pan and see if it matches. 


I believe these first 4l80e versions were controlled by a stand alone controller, so it must be the controller is throwing a trouble code. 


There may be a way to get the controller to blink the light on and off to tell you the trouble code.


First things first, check the pan and see if it's a 4L80E. 

[Oliver GER]

Thank you I will check this in the next days!

[tmsnyder]

At least check the fluid level, maybe they have a low level warning

[Oliver GER]

Hi,
dose anybody know the location form the OBD connector?

[Rickf1985]

I don't think the diesel is OBD controlled, At least it is not in this country. Not until the later years around 96-97 when OBDII came about.

[Oliver GER]

Thx,
I just wounder how to read the error code from the transmision?


is realy funny it's shifts great and smoth but always this stupid light is on. The manual say the trans will only shift in second gear and reverse but mine is OK

[Oliver GER]

Hello,
I found the connector to read the codes but it dosen't help much it always say 12 that mean "no engine speed signal" but I checked the signal from the engine speed

https://drive.google.com/open?id=10xLCoAJuA6hNpBmrIzbkxXlxIMgrZTge

I have no idea it is ok or not

[Rickf1985]

You are reading the engine codes and that may not pertain to the diesel. The diesel gets it's speed signal from the alternator usually. There is probably a separate connector for the transmission controller.

[Oliver GER]

I connect direct to the Speed Sensor for the transmission (on the rear side from the motor (Engine Oil Pump Drive Shaft [/size]https://www.rockauto.com/en/moreinfo.php?pk=88383&cc=1059498&jsn=585))

[Rickf1985]

Ok, That will give you the tach reading but what I am saying is that I do not believe the diesel engines work on the OBD controls. That may be an erroneous reading. The transmission code will be coming in from somewhere else. Try following the wiring from the transmission where it comes out by the shifter assembly and see if it goes to a control unit. If  it does then that unit is what is giving the code. You may or may not find a diagnostic plug there. I will try to get hold of a buddy of mine who has been building transmissions for 40 years, he will know if that transmission is computer controlled or just electronic.

[Oliver GER]

Hi,
I was in a shop to get the life data from the engine and transmission. I have a temperature problem on the engine speed sensor. If the motor gets warm/hot the speed signal is lost.
So I need to exchange the sensor and it looks like not one available in Germany    I think to order from Rockauto they offer the best price


GM# 07849305 or ACDELCO 21597

[Rickf1985]

Here is a good site to join to get information on the 6.2 diesel. It has been so long since I was on there that my login does not work anymore. I have applied for a new login but I have to wait for approval. I used to work on these engines a lot but I have not done so for many years now. I don't ever remember a speed sensor going bad like that but age will destroy electronics like that so it is entirely possible. And the symptoms are perfect for an electronics failure.


https://www.thedieselpage.com/password.htm

[Rickf1985]

Ok, I got into my account and looked up the speed sensor and found out that coupled with the 4L80 transmission you do need that sensor so you are on the right track if it is bad. did not find a part number as I just got in.


""Hi Guys,
I'm in the process to swap my 4l80e in my 84 Suburban behind 6.2l Diesel.
I mount a tps via custom made adapter at the IP in place of the original tpswitch.
Now, I need an engine speed signal, too.
The hole time I thought, it will be easy, because I wanted to use a trigger- or reluctorring from the 6.5l engine with original engine speed sensor und original front cover with ess-opening. Now, it seems that there is NO chance to get that reluctor ring somewhere.
Is that right? Or did I overlooked something?
Btw, is the 6.5 camshaft similar to the 6.2 camshaft in that area, where the reluctor ring and harmonic balancer sit?
How did other guys get the ess from the 6.2l to use it for electronic shifted trannys?""







""If you want the reluctor for the CPK (crank position sensor), you'll need the 6.5 balancer. Otherwise, you'll need to use the oil pump drive ESS generator. Contact www.peninsulardiesel.com for that part.""


Penninsular diesel is out of business, here is the outfit that took them over.


http://www.uniquediesel.com/bolton62.html
__________________

[Oliver GER]

Hi,
I placed the order at rockauto also an HD2 kit for the transmission today.
I will get the parts next week :-)

[Rickf1985]

Is the HD2 kit a Trans-Go shift improver kit? That is the only kit I will use since all the others are geared towards racing. Once you get that kit be sure to read the directions and do not go with the racing setup. That is too hard on the parts due to the shock loads when it shifts.

[Oliver GER]

Thx,
the most important is the upgrade for the oil pump. I will do it with a friend he did a it before and I hope to learn more about working on this kind of transmission. I'm more used to repair stand transmission from old German cars.
My automatic transmission experience is just from the Chrysler Sebring 2.5

[Froggy1936]

Hi Oliver, If the upgrade on the pump is to lower pressure in reverse. I do not recommend doing it . I changed my pressure springs as per instructions, The when backing uphill with my boat hitched up i had major slippage in reverse. The reason for lowering the pressure is possible case breakage. I do not know how often that happens or the conditions under which it happens but i was not happy with that modification ! Frank

[Oliver GER]

Hi Frank,
thanks for this! I will think about this and also du a test drive with the Brave from my friend

[Rickf1985]

I looked up that kit and it is a reprogramming kit. These are generally for cars and high performance vehicles and produce neck snapping shifts. If you do that with an RV you will be breaking things. The regular shift kits are designed to be set up for heavy duty vehicles like RV's and tow vehicles. Once the passages are drilled out on your valve body there is no going back so be sure this is really what you want. If it turns out you do not like it you will be in the market for a new valve body and they are in the 600-800 dollar range over here. And that is with a good core which you will not have so add another 150.00 plus.


This might answer some of your questions.
http://www.transgo.com/faq.html


And here is Trans-Go's home page.
http://www.transgo.com/index.html

[tmsnyder]

You have a 6.2L diesel and a 4L80E transmission.   Personally I wouldn't mess with the 4L80E.   It should last forever behind that low power motor.  I say that with love b/c my everyday driver is a 6.5L suburban with 337,000 miles on it.  Personally I would just do a filter and fluid change and call it a day.  Why ask for trouble?


For parts and advice on that engine I would contact SS Diesel Supply.   They specialize in only the 6.5L and its earlier version, the 6.2L  They know their stuff.  They know the transmission too.


 http://www.ssdieselsupply.com/contact.html