20 replies to this topic

[saltybeefcubes]

Basically I swapped in a different trans since mine was blown. The transmission that is in it now will not shift out of 1st when it's in drive. However, if I manually shift it from 1st to 2nd to 3rd it goes in just fine. Also all my dash gauges (rpm, mph, gas, oil, etc) are all non operational now. My question is: would these two things be related? Because if the car cannot register how many MPH'S it's going would that be the reason that it won't shift to second?

Any insight would be EXTREMELY helpful because I'm legitimately stuck with this.

Edited by saltybeefcubes, 11 April 2012 - 04:34 PM.
grammar

[nipper]

What did you forget to plug in?

It sounds like your transmission is in limp mode. You also will have no AWD.

Did the cluster work before the swap?
Check all your harnesses that you futzed with, unplug them and reattach them. Sounds like somethig isnt plugged back in properly or a blown fuse, or both.

[Fairtax4me]

I thought Limp mode for the 4EAT was 3rd gear only and Locked into AWD?

The TCU takes speed readings from the Dash cluster so if the speedometer is no working that could present an issue.

Like Nipper said, check fuses and double check all connections that you might have had unhooked while doing the swap.

[Caboobaroo]

Apparently we have to guess at what car this is in since you failed to give us that much.

Now if it has a VSS mounted in the transmission, I'm willing to bet it didn't get plugged back in, which is why its staying in 1st and nothing is working. Location of the VSS depends on the year of the vehicle. Check the passenger side of the transmission for a plug, probably going to be near the firewall.

[saltybeefcubes]

Im sorry. It's a 90 LS Wagon FWD

[nipper]

I'm still going with electrical

[987687]

The transmission must "think" the car isn't moving, so it stays in first.
Limp mode is 3rd gear, so it's not going into limp.

Do you have a flashing AT Temp light on startup?

[nipper]

Out of curisosity, do you have reverse lights?

[saltybeefcubes]

Yea, the reverse lights are operative. I do not notice any lights coming up on the dash (though they could be out too).

I was told that the connectors behind the battery that come from the intake manifold have the coolant temp sensor and other associated wiring from the engine. So I'm starting there and hopefully can hopefully figure this out.

Electrical, is VERY frustrating.

[saltybeefcubes]

Ok so all the gauges now work with the exception of odometer and speedometer. Other people having the same problems have discussed the vss as the culprit as well. I've looked for sensor but the Haynes does a terrible job at describing its location for the fwd vehicle

[987687]

Since it's a 90 it has a speedo cable. The speedo cable will go to the gauge cluster where it's converted into a digital signal for the computers.

The speedo cable should come off the front diff (above the front axle area on the pass side) and go into the firewall, into the gauge. Since the speedo isn't working, start with fixing the speedo cable problem.

[saltybeefcubes]

okay will do. My question is what are the chances the speedometer/odometer problem is related to the transmission problem? Or are they more than likely unrelated and the trans is just garbage?

[987687]

Well, if the trans computer can't get a speed signal, how is it supposed to know you're going fast enough to shift into 2nd gear?

Check for trans codes and see if it's complaining about VSS.

[saltybeefcubes]

Well, if the trans computer can't get a speed signal, how is it supposed to know you're going fast enough to shift into 2nd gear?

Check for trans codes and see if it's complaining about VSS.

Awesome. Thank you so much I appreciate the help tremendously! I'm glad to have finally found a forum with knowledgeable and helpful people!

[nipper]

Awesome. Thank you so much I appreciate the help tremendously! I'm glad to have finally found a forum with knowledgeable and helpful people!

who, where ...

[saltybeefcubes]

Welp, I checked the trans code (both current and previous) and they both came back normal. So it's obviously the speedo cable. Now which part of the cable, I don't actually know, but I'm hoping that it's not the part that goes into the dash and is the part that plugs into the transmission.

Now if it is only the cable, is it still a possibility that it's effecting the transmission? Or is that probably a no go since all the sensors are fine and the trans is just bad?

[nipper]

Actually you hope it is the cable or the head, not the trasnmission end.

[Fairtax4me]

Perhaps we should make sure the cable is attached properly first. It attaches to the transmission on the passenger side a few inches behind the gear oil dipstick. There is a short section that threads into the transmission case (maybe 6" long) and the cable attaches to that with a small metal clip to hold it in place.

[saltybeefcubes]

So my biggest question here is:

Could the cable being bad really mess up the transmission to the point of not shifting past 1st?

[nipper]

How automatics work.

Automatics shift by balancing line pressure vs govenor pressure, with the throttle giving input to shift points. On a modern car, the govener is gone, replaced by electronics. Both relied on car speed to give feed back to the tranny to know when to shift. With a stuck govenor, you would get only 1st gear (or late shifting depending upon the issue). The same is true with a dead spedo.

On cars with two VSS (in the transmission) if one fails the other takes over, but the AWD is deactivated.

You can override the "govenor" input, which controls the shifting, by manually shifting.

So yes it can keep it from shifting in years with cables

[saltybeefcubes]

How automatics work.

Automatics shift by balancing line pressure vs govenor pressure, with the throttle giving input to shift points. On a modern car, the govener is gone, replaced by electronics. Both relied on car speed to give feed back to the tranny to know when to shift. With a stuck govenor, you would get only 1st gear (or late shifting depending upon the issue). The same is true with a dead spedo.

On cars with two VSS (in the transmission) if one fails the other takes over, but the AWD is deactivated.

You can override the "govenor" input, which controls the shifting, by manually shifting.

So yes it can keep it from shifting in years with cables

awesome, that's good news because my cable was bad on both ends. I easily fished it through the fire wall so it obviously wasn't attached to the dash and the little plug into the trans also looks bad as it appears that the little "flat head looking piece" snapped off in the old transmission and it also fell out of the plug once it was removed from the tranny.