Forgive my ignorance... Please tell me, what is a TCU?

[maxnix]

3rd gear only is fail safe mode. Remember you start in 2nd.

Have the TPS "mechanic" check the connection again. Then perform the AT diagnostic per the manual if it still doesn't shift.

[heatherin951]

I know i start in second...it wont come out of second. I can manually shift from first to second....but nothing else. not counting reverse of course.
Modified by heatherin951 at 11:45 PM 8/30/2008

[SteveTheTech]

Hi there,I think something might be over looked. You said earlier that your TPS connector was loose. There may be another or separate issue, but its worth looking into.If you loosing throttle position to your ECM it may cause it to get stuck.

If your terminal is breaking contact at the TPS it can be verified or ruled out by inserting a terminal of the exact size (maybe a male terminal off the old TPS). If there is resistance you know that your terminal end is ok. (If I can get Acrobat to stop crashing my browser I will post it) Secondly you may want to check terminal #3 at the TCM with a digital multimeter set to DC voltage while driving. If the voltage does not match throttle input while the incident is occurring you have no input signal.

These are just a few simple tests, if you are able to retrieve any DTCs from the transmission maybe theres another direction to go in, Its just something I would look into. Especially since it only seems to happen intermittently.Good Luck

[heatherin951]

thank you Steve!!!!

one thing tho...its no longer intermittent.

and.....Go Pats!!!!

I went to their playoff game at the Chargers 2 seasons ago.....was one of about 300 Pats fans with 68,000 Charger fans. I'm a Pats fan from way back!...just sayin'

[SteveTheTech]

Thanks for the support us Pats fans have had a rough past few months, and deserve a break lol. I have finally come to terms with not only a perfect regular and post season and choking at the end but loosing to little Manning still stings. We'll be in Tampa this year though Randy wants a ring with the Pats logo. Anyway that's a different story.

Back to your concern,

Since it is no longer intermittent it may be able to be found now. If the TPS circuit is ruled out, it may be worth looking at the kickdown switch. I really have not seen too many issues with this sensor but it sends the signal to the TCM to upshift when the gas pedal is depressed heavily. This sensor is adjustable, much like a brake switch and may be out of adjustment, sticking, or open. The component inspection of this sensor is pretty straight forward and may be detectable depending on the scanner used. I sort of doubt it is your issue but it could not hurt to check.

If that checks out it seems like you may have a sticking solenoid. According to the transmission brake clutch application chart in the AT section of the ESM it says that the brake band is applied in second and pressure is applied to the release side to engage third. If your trans is not applying to the reverse side you will not have third. The high clutch is also applied in third which transmits input power to the front planetary carrier if the clutch has failed you would have an issue but I think you would have a different concern. A mechanical issue will also not produce a relative DTC and is not a very fun fix the diagnostic procedure requires removal and disassembly of the unit before any decision should be made

So does the engine bog down or does it just stay in second the entire time with no effort at all to change gears? I am hoping that there is an on vehicle fix for this that will not require you to buy a whole new transmission.

[heatherin951]

Admitttedly, some of what you say is greek to me. LOL. I will however show it to the friend that has been helping me.

I can feel it try to shift. It feels like its going to, then doesn't. Its running great though. The friend I said has been helping me can actually get it to shift. But it has to be on a certain incline at a certain RPM. Anyway, thank you so much. i will keep you posted.Heather

[maxnix]

So tell us about the white paper towel test resuts for the ATF, please.

[heatherin951]

whaaat?

[SteveTheTech]

The paper towel test is a great idea at this point. You need a clean white paper towel, take the dipstick out of the transmission filler tube and wipe some of the fluid on the towel and look at the color. This is to see if there are any friction material or metal in the fluid.Or at least that's how we do it. Since you have already changed the fluid I do not know how accurate this will be now.

So you say that while you are going up an incline and throttle position is increased (depressing the pedal) it will upshift? If so upshift to what first? What speed are you going when this happens? If this is the case maybe your revolution sensor is the issue, as output shaft speed decreases (detected by the revolution sensor) and throttle position increases(accelerator pedal angle) the TCM should send the signal to upsift. This may indicate a problem in your revolution sensor. This is assuming that your throttle position sensor circuit is in good working order.

[heatherin951]

it will shift for him from second to third. at high RPMs, and going DOWNHILL.

[SteveTheTech]

Yeah it sounds more like an electrical input signal error somewhere, either in your TPS or Revolution sensor. Now that's just a blind guess since I cannot drive it I can't really be sure.

[heatherin951]

Thank you Steve. I will check it out.

<<<i just think thats funny as hell.

[heatherin951]

Hi guys!

My mechanic that has been out of the country is on his way over to look at the Q.

She has been sitting waiting for him for a week.

He knows her inside and out. I bought her from him. He replaced her motor, brain, dash, timing chain, and a handful of other things before I got her.

So I will know once and for all what the heck is really wrong with her.

He is going to have my *** cuz she is dirty. LOL.

I will let you guys know what the verdict is later today.

Thanks again for all your help.

Heather

[SteveTheTech]

Good Luck, Hope its nothing too bad.

[heatherin951]

ok he post poned till tomorrow. <<<it is saturday so what the heck.

[SteveTheTech]

I'm practicing for tomorrow

Go Pats!!!

[heatherin951]

Welllllll.....

Off she goes to Infiniiti of Riverside tomorrow...for diagnostics ( ONLY! ).

My mechanic (Mechanical Mike as my 5 y.o. calls him)... narrowed it down. There is a simple break in a connection somewhere. I'm sure I'm not saying it right. In any case, it is a corroded wire, or bad solenoid. For sure not the transmission. He actually jiggled when i told him I had a new TPS put in it while he was out of the country. I didn't find it humorous at all...just sayin'.

So...soon as it cools off outside I am going to spit shine her up. I figure the prettier she is (being 18 years old and going to the dealer for Ch#*&%'s sake), the better her chance of being treated with respect tomorrow. ...Point being maybe i will take a decent pic after i get her all shinier. I will post one if I can get a good one.

Just sayin' .Heather

[maxnix]

A clean car with a clean engine bay is like going to the hospital with clean underwear. Much better attitude from the technicians.

You know you can run the AT diagnostic yourself and determine if there is any electrical inconsistencies?

[heatherin951]

The AT diagnostic showed absolutely nothing. I have read on this site that the early Qs self diagnostic computer can be....insensitive, or may not pick up on the not so obvious. Anyway, so glad to hear you say it DOES make a difference when a car is very clean.I can't imagine the Techs at the dealership see too many 18 year old cars in their bays.Who knows though.~H.

[AZhitman]

My bet is a bad connection in the TPS, and cleaning the contacts and coating with dielectric grease might be all she needs.

[heatherin951]

AZ....did it today. wasn't it. LOL

I so dig you guys.

Ok pics. No judging. it was gettiing dark...she wasnt really polished up. And she is embarrassed about the missing hubcap. Happened a couple weeks ago before all this started. What REALLY Stunk about it was I spotted it the next day. On the brand new 91/60/215 interchange! At the highest and most pivoting point of a huge freeway bridge. So I couldn't get it. Been looking for a replacement, any ideas...?Anyway, be kind. she isnt perfect. I just dig that you guys dig the kinda car I dig. LOLok i guess not...im not paying to upload pics....is that for real???

[heatherin951]

Modified by heatherin951 at 1:17 AM 9/8/2008

[maxnix]

If AT diagnostic showed no problems, then electronics in AT and TCU probably not the problem.

[SteveTheTech]

It doesn't mean that there is not a problem the older vehicles control units have less long term trip logic, and in some instances wider DTC detection thresholds.

I don't know if I am missing something in this thread but what happens if you manually shift the car through the gears as you drive? I took a quick run through it while writting this and very well may have missed the answer to my question. Did they peform any electrical input tests when you had it serviced. The numbers may look good one the screen but the TPS should be set off resistance value per the ESM.

I agree with AZ and still think either the TPS pin fit is loose of the connection is not tight. It sounds like one of those as* kicking bugs.

Oh and a quick poll of me and the other Master here and its unanimous agreement that a clean engine means someone loves their car and... I am hesistant to say it gets better service but I always put in some extra effort to keep it in top shape and make sure the connectors vacuum hoses and covers are clean and pretty when it leaves.

[maxnix]

It also helps when the tech isn't trying to see through layers of grease and grime when hoses and connections are checked.
Modified by maxnix at 12:36 AM 9/18/2008

[dusred]

I'm glad to see you guys (and gal(s) ( ) figure this problem out.

You can email me or Wes the pictures and we can host and post them for ya.

Good luck on figuring out the issue, I'm in suspense to see what the real issue is.

[heatherin951]

Soooo...

Took her to Infiniti of Riverside. Was herded into their "lounge" for over 2 hours, just to have them tell me I would have to come back the next day. This was with an appointment I made 3 days in advance.So I didn't go back.Anyway, I think its safe to say at this point I need a transmission. She started slipping.I am curious what the suggestions are here when looking to buy a transmission. I have the labor handled.What is the benefit of getting a first gear start?thank you for your input.Heather

[Infinitiguy19]

Its sucks that its your transmission, But sometimes the stealership says to replace a big thing to fix someting small.

But first grear start just aliveates the stress on the transmission so it shifts eaiser and smother.

what about a drain a refill and adding an external cooler have you done either maybe those can save your transmission.

[heatherin951]

The drain and refill was the first thing i did when this all started.

I don't know what an external cooler is.

[heatherin951]

i just realized i typed jiggled instead of giggled.