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shifting issue-- Please help

C

clgarrison

New member
Please be patient while I try to describe what is going on the best I can...

First of all when you turn the car on everything is fine. When you shift into D it sounds like it is shifting, but when you go to accelerate you have to put the pedal almost to the floor before you start moving. BUT if I were to shift into first and then accelerate, it accelerates fine. Once I get to higher speeds in D it sits at around 3000-3500 rpm, but if I let off the gas it goes down to 1000 rpm and then if I get on the gas again it jumps right back up to 3000-3500. BUT it doesn't do it all the time. Sometime I can turn the car on and it doesn't act up at all and drives like a dream. And sometimes it will start out fine and I can be cruising along at around 60 and the Airbag light will start blinking and then it seems to "fall out" of OD and the RPM's jump up. Cruise control will work when it isn't acting up and then it will go out as well.

I checked the wiring harness for any shorts and I also checked the fuse box. I was advised by someone to flush the trans and put in a new filter. Just confused at this point as to why it would be intermittent like that.

Any ideas or suggestions?
 


sounds like your forward band is shot. When you are 1 and 2 manual it is a different band in the trans and allows you to move.
 
I wouldn't think that if the forward band was shot that it would work on and off. It drives perfectly fine sometimes and then other times it won't.
 
Yup, sounds like your foreward band to me. Classic sign.

Taken from Wont move in D or 3 only

No Movement with shifter in "Drive" or "3" range:


This problem has really surfaced in the past few years with the 4T65E transmission and will catch you off guard for seemingly no reason.

Here's the scenario-

You are driving along just fine and no reason to suspect any problems. You make a stop at the gas station or grocery store and when get back to your vehicle you start the engine and put the shifter into Drive and nothing happens. Not believing that this is really happening you move the shifter between Park and Drive again and still nothing. If you have tried moving the shifter around more you will have found that the vehicle moves fine in Reverse and will also pull away in 2nd and 1st ranges.

If you have ran into this problem then you likely have a broken Forward Apply Band. I see more of this on the 00-02 model years but it does occur on other years as well. Unfortunately a broken forward apply band means a full rebuild to replace as it is one of the last parts to come out of the transmission case during teardown. There are numorous thoughts and opinions as to why this happens but there really isnt a definate answer, and being that this is more of a year related condition that makes it more difficult to track down the cause. High line pressure is going to be brutal on transmission parts, and I am not just referring to WOT driving conditions. Pressure problems in general in this transmission are going to cause trouble at some point in time. Code P1811 puts the transmission in max line pressure once it sets and can be another culprit and maybe why it is not found as often on the 03+models because there was a newer designed pressure control solenoid used that didnt have near as many problems as the earlier versions. Regardless the route cause of WHY the band broke, it is broken and needs to be replaced. Below are a few pictures of forward apply bands and how you can tell if yours has broken or not. One picture is of a good band, a fractured band that was on its way to failure, and a broken band. Sometimes you may find about a 1" piece of metal from the band laying in the lower transmission pan when you drop it for inspection. Other times the lug will tear on the band where it is brazed on.
Click to expand...
 
maybe a crack starting in the forward band and sometimes it's grabbing decently. Soon..it'll probably not work at all in D/3
 


Well... I did some reading and found that a wheel sensor can cause the traction control light and ABS light to come one (which both of mine were on) and so I replaced a bad connector. Got in, took off and I thought it was fixed... came to a stop and went to take off and NOPE! It acts like it is starting in 3rd and not downshifting to 1st. It is probably going to end up at the shop this weekend... damn.
 
my confusion is coming from the symptom of the air bag light coming on and flashing. what does the air bag have to do with the trans. still very hesitant to remove major components to inspect them.
 


clgarrison said:
my confusion is coming from the symptom of the air bag light coming on and flashing. what does the air bag have to do with the trans. still very hesitant to remove major components to inspect them.
Click to expand...

If the transmission is turning over but the wheels are not going anywhere, it can make the PCM throw up all kinds of flags. One of which could be the air bag light.
 
Zef...i've never head of that, is that something you read or are thinking? It's certainly interesting.

Does the airbag only flash when you are slipping?
 
BillBoost37 said:
Zef...i've never head of that, is that something you read or are thinking? It's certainly interesting.

Does the airbag only flash when you are slipping?
Click to expand...

I remember reading that somewhere. Like if you break an axle or output shaft, the trans will think the car should be moving somewhere, but it isn't, based on the WSS and sensors in the tranny.

I'm not 100% sure that is true. But makes sense in my mind.
 
Neat..

I have done a WSS kill switch to override TM (my car) and never got an airbag. That was a 97 Bonnie though. Lucky it had a bag.

Typically I've only come across the bag light being something in the bag system showing a fault. Like the connector under a seat (on side bagged seats in Regals) and other bag type connection issues.

Always looking to learn something new though. Cause stuff like this is what helps a guy diagnose something quicker.
 
Well there seems to be no rhyme or reason for the failure to happen. Hot, cold, fast, slow, 1 hour, or 10 minutes... However every time it fails it throws the "SRS air bag" light on the dash flashing. Some times it will stay lit and other times flash randomly and go back to full lit. The true symptoms are no first gear, no over drive, and in drive it has no downshifting, in 3rd it is the same as drive, in 2nd it will downshift to 2nd, and in 1st it is the same as 2nd. when accelerating in drive and 3rd there is no 1st or 2nd, in 2nd or 1st there is only 2nd gear. The major hang up, and thing that is making me believe it is electrical is that i could go out and drive it and it will be fine. Stop some where and it will fail. Stop somewhere else and it will be fine. continue driving and it will fail mid stride. and it never fails slowly such as with a slipping trans. There is no jerking, jolting, or power fade.
 


I'm going to buy a good manual with good electrical schematics to troubleshoot it proper. Seems like a short to ground or to another source (air bags).
 
I understand what you are after. Seeing the two circuits and where they draw power and ground from in an effort to find a correlation.

Been there..done that.
 
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