4l80e and 1989 6,2D

**Sceolan** · 12-07-2007, 04:01

Hello.

I've replaced the tranny in my 89' G30 6,2 Van from a 3-speed to an 91' 4l80e. This seems to work fine, speedo works and I don't get any error codes in the system.

But I have one question. When I floor the throttle, the tranny shifts from 1-2 at around 42km/t (26mph), and from 2-3 at 82km/t (51mph). I mean it should go up to around 60km/t (37mph...) before it shifts from 1-2, and close to 100km/t (62mph) before it shifts from 2-3.

Isn't that true? I'm not sure any longer

I tried adjusting the TPS, but still the same.

**convert2diesel** · 12-07-2007, 06:50

What controller are you using to drive the new tranny. If it is looking for some engine components that aren't there then it may have gone into some form of default mode.

Bill

**Sceolan** · 12-07-2007, 07:22

Hey.

Im using the original TCM that was previously used for the transmission when it was in the "part car". Ive transfered all the wires from this TCM from the "part car" and over to my 1989 Van, including the VSS and so on.

I hope you understand what Im writing here... :-)

**convert2diesel** · 12-07-2007, 09:56

I guess what I'm saying is what was your original "parts car". That will dictate how the TCM/ECM was originally programmed. If the parts car was a gasser then the ECM is also looking for:

Manifold pressure
Mass airflow
O2
Engine temp
TPS
Engine speed (RPM)

Even if the parts car was a diesel, it may also be looking for EGR and it will definitely be looking for an engine speed sensor.

If it does not see any of these inputs, it will more then likely go into one of the default modes that will directly effect how your tranny shifts and weather or not the torque locks up.

Bill

**JohnC** · 12-07-2007, 11:05

Any idea what RPM it's shifting at? MPH depends on the transmission ratio and rear axle ratio.

**Sceolan** · 12-07-2007, 11:23

Originally Posted by convert2diesel

I guess what I'm saying is what was your original "parts car". That will dictate how the TCM/ECM was originally programmed. If the parts car was a gasser then the ECM is also looking for:

Manifold pressure
Mass airflow
O2
Engine temp
TPS
Engine speed (RPM)

Even if the parts car was a diesel, it may also be looking for EGR and it will definitely be looking for an engine speed sensor.

If it does not see any of these inputs, it will more then likely go into one of the default modes that will directly effect how your tranny shifts and weather or not the torque locks up.

Bill

Hello.

The parts are coming from an 2 year newer car, (1991) witch is also an 6,2l D G30 Van.

I havent thought about that it might be looking for EGR... Do you think that might be the reason?

Engine speed sensor is moved over. I guess my speedo wouldn't work if this speed sensor didn't work... The instrument panel is moved over from the part car, speedo and so on, because my old speedo was linked to the old transmission by a wire.

**Sceolan** · 12-07-2007, 11:33

Originally Posted by JohnC

Any idea what RPM it's shifting at? MPH depends on the transmission ratio and rear axle ratio.

I don't know, but I would have liked to known

This transmission have the same gear ratio as my old one in the first, second and third gear.

**convert2diesel** · 12-07-2007, 12:07

Okay two things

Are you sure you have a 4l80E? Personally I have never seen the 4l80E in anything older then a 93. Doesn't mean they didn't exist, just that I have never come across one. More then likely you have the 700r4. How many wires are coming out of the side of the tranny? The 700 has only 4 or 5 (2 for the VSS and 2 or 3 for the lock-up). The electronic tranny will have a sizable bundle of wires coming out of it (not sure how many).

The engine speed sensor is either a seperate wire coming from the alternator or a sensor built into the oil-pump drive located at the back of the engine in the valley on the right hand side. Should have two wires coming out of it. This is not the "vehicle speed sensor" that is mounted to the tranny. That is used to drive the speedo. The one I'm talking about only senses the RPM of the engine.

Bill

**EWC** · 12-07-2007, 14:35

The 4L80E trans was installed in the 2500 and 3500 trucks , vans in 91 . His system is very simple only needing RPM , TPS and the electronics to run the speedo . I have a 95 system and the only sensor in addition to the above is a baro sensor . No EGR is used . This is on the 6.2/6.5 Y engine in the van . i just picked up a harness for a 91 Suburban with a 6.2/4L80E combo and that does not have EGR .

**convert2diesel** · 12-07-2007, 15:25

I stand corrected. You learn something new everyday.

That would mean that there are a number of these standalone controllers just sittin around in bone yards. Certainly better then the 1000 clams the aftermarket is getting for these controllers. Maybe a viable alternative for my B/D chassis conversions. Anyone have a list of the chassis these were used in?

Bill

**EWC** · 12-07-2007, 20:41

I've seen them listed for parts up to 97 in bread trucks . The G vans are an engine code Y , that means 6.2/6.5 NA engines . If you find one with a turbo , keep looking as the ECM also operates the DS4 . Ebay has a TCM right now for sale . The 91-93 TCMs were the same , 94-9? had a different part number . Keep the years the same as the TCMs went to a different baud rate ( as per Bobbie Martin ) after 93 .

**Sceolan** · 12-08-2007, 06:52

Originally Posted by convert2diesel

Okay two things

Are you sure you have a 4l80E? Personally I have never seen the 4l80E in anything older then a 93. Doesn't mean they didn't exist, just that I have never come across one. More then likely you have the 700r4. How many wires are coming out of the side of the tranny? The 700 has only 4 or 5 (2 for the VSS and 2 or 3 for the lock-up). The electronic tranny will have a sizable bundle of wires coming out of it (not sure how many).

The engine speed sensor is either a seperate wire coming from the alternator or a sensor built into the oil-pump drive located at the back of the engine in the valley on the right hand side. Should have two wires coming out of it. This is not the "vehicle speed sensor" that is mounted to the tranny. That is used to drive the speedo. The one I'm talking about only senses the RPM of the engine.

Bill

Yes, I am pretty damn sure that it is an 4l80e

This I have checked and rechecked during this project.

But you are saying that there is 2 speed sensors, vehicle and engine speed sensor, and the one that is "driving" the speedo is locaded on the transmission. This is interessting...

Now Ive got something to check, maybe it is this engine sensor that is not working correctly, this sensor on the rear of the engine with 2 wires going from it.

But the roads here is damn icy at the moment, so I guess I should wait a few days before testing

Frank

**More Power** · 12-08-2007, 16:10

The 4L80-E was first introduced in the 1991 model year bigblock and diesel equipped pickups and SUV's.

Jim

**Robyn** · 12-08-2007, 20:51

This is interesting and possibly it is a production anomaly.
I had a 91 Diesel Burb and it had a 400 in it. Dont think it was a retrofit either.
I had another 91 Burb that had the 700R in it. 1500 series though

Was the 4L80 an option or ???????

**EWC** · 12-08-2007, 21:10

The 400 should have been a refit . Could check the VIN to make sure it wasn't a late 90 . I had a 2500 Suburban fire truck that had the 4L80e , have a 5.7 with one in it sitting in the yard now beside a 3500 crew cab with a 5.7 and the 4L80E . Really , how would you know that the TH400 was a refit ? Lengthen the drive shaft and move the cross member forward and it looks right . I pulled the shift linkage off and that was only about 2" longer than the TH400 and the cross bar looks like a TH700R4 side by side . The support for the " Z " bar is a little taller and wider but I did talk to someone that just used the 700 stuff and it worked . The harness that I just got was supposedly from a 91 Suburban 2500 with the 6.2/4L80E combo and I believe it . There is the plug for the trans , both speed sensors ( big tip off as the 700 only has one sensor ) , glow plugs , TPS , fuel filter , engine RPM , etc . The option code is also correct , MT1 . The 700 is MD8 .

**More Power** · 12-08-2007, 21:38

I should have added the 4L80-E only went into the 3/4 or 1-ton models.

I saw a 1991 diesel Burb a couple of years ago that was in for trans service at a local trans shop. It had the OE 4L80-E.

Jim

**Rondane** · 12-09-2007, 06:22

Originally Posted by More Power

I should have added the 4L80-E only went into the 3/4 or 1-ton models.

I saw a 1991 diesel Burb a couple of years ago that was in for trans service at a local trans shop. It had the OE 4L80-E.

Jim

Hi, I can see one right now, trough my officewindow.

Hei Frank, vanskelig for disse amerikanerne å få inn i hue at Suburban kom med denne kassa i -91.

Sub6291 på offroad.

**Sceolan** · 12-09-2007, 07:17

Now I've just checked my wiring to the Engine Speed Sensor, and found out that there maybe was some wrong there, but I corrected this using the Fig 15 on this page, http://www.autozone.com/az/cds/en_us...rInfoPages.htm

So I am now pretty sure that my Engine Speed Sensor is connected correctly.

But when I took it for a spin today, it still shifted at the same speeds as before. So maybe my Engine Speed Sensor is not working as it should...

**EWC** · 12-09-2007, 11:38

You should have an engine speed sensor and 2 trans sensors .

**EWC** · 12-09-2007, 12:27

Just took a look at the wiring from Autozone . That's not what I'm used to looking at . What year is yours , 91 ?

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