Probably Tranny Problem

[jqzhang]

Hi,

My 1991 LS400 started having problem yesterday, after I changed the drive belt.

Here is the symptoms:

1) when driving, as I press brake pedal, the shift light on the dashboard lit up and the rest of the lights on the board are all gone; releasing the brake, all lights back to normal.

2) when shifting from N to D or from R to D or from P to D, it's rough but used to be smooth. But there is no problem accelerating and shifting for now.

I'm going to check the code see any code coming up; also check the stop light switch. Hopefully the tranny is not dying. BTW, I checked the fluid too, it's pink and no bad smell.

Thanks in advance.

[python]

u have the famous trunk wiring harness issue. on the drivers side hinge on the trunk lid is a harness that u need to look at, u have a wire in there that needs to be fixed.

[eatingupblacktop]

u have the famous trunk wiring harness issue. on the drivers side hinge on the trunk lid is a harness that u need to look at, u have a wire in there that needs to be fixed.

You know Python, I'm not feeling the "COMMON ISSUES" pinned threads for this section. To find anything on this topic, you have to skim through far too many unrelated topics. This is such a common prob that keeps getting posted relentlessly, I don't understand why the mods haven't dedicated a pinned link to a merged thread on this topic. Anyone else think it's about time? Wadaya say mods?????

[jqzhang]

Thanks Python.

I checked the trouble code. It's 41: TPS problem (probably ECU, but I'll take my chance of assuming ECU's OK). I guess I have both: the trunk harness and TPS. Don't you think so? Can I have some details about how to fix the trunk harness?

Thanks again Python!

[fsuguy]

Thanks Python.

I checked the trouble code. It's 41: TPS problem (probably ECU, but I'll take my chance of assuming ECU's OK). I guess I have both: the trunk harness and TPS. Don't you think so? Can I have some details about how to fix the trunk harness?

Thanks again Python!

jqzhang,

Look at the left hinge of your trunk - there is a cluster of wiring that goes to the taillights; the wiring from the factory was probably too short and due to flexing over time, either one or more wires in the cluster break inside the insulation causing a variety of odd problems. You will need to first release the wire bundle from the hinge, then unwrap the electrical tape around it. Now this is the difficult part - you will need to check each of the wires separately to find out whether it is broken inside its insulator. If you are "lucky" the break will include the insulator. You probably should check the yellow wire first, then the black ones.

HTH

Mike

[jqzhang]

Python & fsuguy,

I cannot help saying that you guys are incredible. Really, I mean it. Following you guys' comments, I have it fixed, even not completely.

I don't know why but mine is slightly diff. from what you mentioned. I saw a picture that CUMan posted (I guess). It was a 12 pin female socket so you have to find out which wire is really broken. Mine is easier. About 5 or 6 wires covered by a black plastic box with the size of a small Bic lighter (too bad I don't have my camera handy). The broken wires are just right there for you to pick: a grey and a white.

I said 'not completely' since the remote for trunk opening is still not working. I suspect there be some more broken wires that I haven't found yet. Don't you agree?

But at least the weird response of tranny is gone and the shift-lights on the dashboard come back normal, thanks to you guys.

I was curious, very much. How the heck you guys found out about the trunk wiring harness was the culprit? I believe most of the dealership won't be able to pin-point the problems either. They may go through the routine that I did: check the trouble code first. Then I would change the TPS for nothing, so would the dealership.

Again, you guys are great! I really appreciate your help.

[python]

its just a common issue with these cars.

[1990LS400]

How the heck you guys found out about the trunk wiring harness was the culprit?

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's.

Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!".

[gabep]

It seems to be a common Toyota problem I found the same thing on My 1994 Camry.

[jqzhang]

How the heck you guys found out about the trunk wiring harness was the culprit?

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's.

Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!".

[jqzhang]

How the heck you guys found out about the trunk wiring harness was the culprit?

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's.

Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!".

The remote for opening the trunk is not working for a while. Does that have anything to do with the broken wires? If it does, how come it's still not working after the wires are fixed?

thanks in advance.

[VBdenny]

I have to agree that a pinned link is needed for this issue. I see this simply, easy fix problem resurface often and even after all my years on here, I still can't ever find much with the search.

[steve2006]

How the heck you guys found out about the trunk wiring harness was the culprit?

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's.

Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!".

The remote for opening the trunk is not working for a while. Does that have anything to do with the broken wires? If it does, how come it's still not working after the wires are fixed?

thanks in advance.

Check to make sure the key lock near the trunk release isn't locked in as this disables the remote release, if it is in use the master key to unlock it