J30t Transmission Prob... Need Suggestions...

[halfbyte]

Greetings all NICO members... I am a new user here at NICO and let me tell you this site rocks...

I need your expertise on my 1994 J30t transmission problem.

SITUATION:It don't want to shift from 1 -> 2 gear with in the first 3-5 mins of driving; perfect shifting after that

WHAT I HAVE DONE:Did the complete flush with pan drop and replaced the filter, gasket, and O-ring (Mobile 1 ATF). No luck so far though....

ADVICE NEEDED: I have read most of threads with similar problems and this is where I need you guys help. Should I take the car to a dealer and run the diagnostics with CONSULT? (costs US $90) or should I buy a revolution sensor (costs US$135) and try it? Any advices?

Thanks in advance.-A guy with 1994 J30t with 87K miles.

[cweberj30t]

I would have them do a diagnosis before I'd run out and buy a revolution sensor.

[driverdriver]

I'm not exactly sure what your problem is, Is it that your transmission won't shift from first to second gear in the first 3 to 5 minutes of driving?

Whereareboouts are you located? Are you up in the northern part of the U.S. or somewhere in Canada?

Do you let your infiniti warm up the first time you startesd up in the day, before you drive off? It is an almost a decade old vehicle. I let mine warm up for at least 10 minutes or to whenever the coolant needle starts moving before driving off, or I'm dealing with hard shifts till the car fully warms up (BTW this is normal on all J's).

I would strongly recommend getting a diagonsis first before running out and buying a rev sensor, it could be on of your transmission solenoids or something else, and I would strongly recommend going to an Infiniti dealership where they have a transmission tech on staff. When, I had my transmission issues back in the late fall, I took it to a couple of "chain wide" transmission shops. They recommended I rebuild the transmission. The transmission tech at the Infiniti dealer found the real problem.

[halfbyte]

I'm not exactly sure what your problem is, Is it that your transmission won't shift from first to second gear in the first 3 to 5 minutes of driving?

Whereareboouts are you located? Are you up in the northern part of the U.S. or somewhere in Canada?

Do you let your infiniti warm up the first time you startesd up in the day, before you drive off? It is an almost a decade old vehicle. I let mine warm up for at least 10 minutes or to whenever the coolant needle starts moving before driving off, or I'm dealing with hard shifts till the car fully warms up (BTW this is normal on all J's).

I would strongly recommend getting a diagonsis first before running out and buying a rev sensor, it could be on of your transmission solenoids or something else, and I would strongly recommend going to an Infiniti dealership where they have a transmission tech on staff. When, I had my transmission issues back in the late fall, I took it to a couple of "chain wide" transmission shops. They recommended I rebuild the transmission. The transmission tech at the Infiniti dealer found the real problem.

I have read your thread relating to your transmission problem back in fall as you have said. And Yes I am having a problem exactly like yours... I live in Virginia US and I do let the J warm up the first time.I have an appointment setup for diagnosis. Thanks to you guys... I will keep you guys posted.Thanks.

[halfbyte]

Hello all,

I dropped off my J this morning for a diagnosis (CONSULT) at the Nissan dealership. Inifiniti dealer is about 40 miles away from my place but nissan is 2 miles...

I just got off the phone with service representative and he basically said CONSULT did not show any error codes and suggested that I replace the transmission

I have insisted to check it again as "DriverDriver" has picked up the error code on the third day of test drive. They are going to re-check.

I am wide open for any suggestions on this matter. I just can't believe that I have to change the transmission...

Thanks in advance.

[halfbyte]

Well... got a call and they literally gave up and recommended taking it to an Infiniti dealer to get it checked. They are not going to charge me though...I am going to try to have all the sensors (as many as I can reach...) checked using ohm meter this weekend. I have access to 1994 J30 Service Manual for the weekend. Worst case, I will take it to Infiniti dealer...

[driverdriver], I have a question for you. When you replaced your revolution sensor, you said that they had to do something to ECU? what exactly was that? Service Manual doesn't mention anything about ECU. looks like just one bolt to remove...

Thanks.

[chuongcom]

Could someone please tell me how to test sensor with the meter. Thanks.

[boomstriker]

Save your money and do a basic check yourself.Use the shop manual that came with the car. It explains how to run self diagnostics and get the codes with the check engine light.If there is a sensor bad, it will tell you.If you don't have the book let me know and I can post my '93 procedure.

How do you mean it won't shift to 2nd until it's warmed up? You mean it won't shift no matter how high you rev it?Does it shift when you use the stick to manually shift it?Does it shift fine after it's warm?

I rebuild these quite a bit- they're very easy and parts aren't too bad if you know where to get them.Let me guess- the dealer wanted $2000 for a new trans and another grand to put it in?Kirk

[carlos_knology]

Could someone please tell me how to test sensor with the meter. Thanks.

Get a hold of a service manual. They can be found on Ebay for around $30. Get the real manual, not those CD versions.

All the diagnostic/testing procedures are in there.

[halfbyte]

OK, I just did the sensor diagnosis using the ohm meter according to the service manual.

[ numbers indicate the Terminal Numbers at A/T control unit]25. Revolution sensor -> OK 26. Turbine revolution sensor -> OK27. Vehicle speed sensor -> OK33, 34 Throttle position sensor -> NG

Further throttle position sensor diagnosis shows the following...According to the service manual when the accelerator pedal is completely released resistance must be approx 1.7 k ohms and approx 10.5 k ohms when completely depressed. I am only getting 0.87 k ohm when completely released and 7.8 k ohm when completely depressed.

I am going to order the TPS and replace it. Will see what happens.

[boomstriker]How do you mean it won't shift to 2nd until it's warmed up? "It won't shift to 2nd within 3-5 mins of intial driving..."

You mean it won't shift no matter how high you rev it?"Yes"

Does it shift when you use the stick to manually shift it?"NO"

Does it shift fine after it's warm?"YES"

Problem is very intermittent..

I will keep you guys posted as it progresses. I hope it's TPS

Thanks.

[halfbyte]

Where can I buy an OEM Throttle Position Sensor? is infinitipartsusa.com ok?

[driverdriver]

My problem was intermittent just like yours. It took 3 friggin days of testing it while driving with the scan tool attached for the sensor to trip. I think the transmission tech tripped the sensor on his 8th or 9th drive around the city in stop and go traffic. He would let the car sit for 2 or 3 hours between drives to "cool down". The tech told me he would take the car out on city streets for at least a 20 minute drives preferbly in stop and go traffic.

I am not excatly sure what they did to the ECU.

If possible take it to another dealer. I would also suggest calling a Infiniti's customer support line to find out if their is either a Nissan or Infiniti dealer in your area which has a dedicated transmission tech (basically factory trained tech who only works on Nissan transmissions). I was led to believe in my dealings with the dealer I went to that every major metropolitan city in North America at least has one.

[halfbyte]

Thanks driver....I will try what you have suggested as well.

[Just a thought] Most dealers and tech WILL not (NOT WANT TO) go through what your tech has gone through ... 3 days of test drive with scan tool attached, stop and go traffic, few hours of cool down in between... It just don't happen unless you know the person or something... All (sorry, majority of) the dealer really wants is to sell cars and change engine oil while under warranty...

NICO is far better than any dealer with qualified tech unless you still have a warranty... just my .02

[Q45tech]

The problem is a dealership is use to $150-$200 per hour parts and labor and the techs needs $20-22 per hour plus parts override to live.

Diagnostics must be paid for.

We recently had a G20 that took 8 paid hours to find the no start problem/towed in............[and 4 days to fix].........short in wiring harness that destroyed ecu by putting 12 volts on a 5 volt max line.

$ 560 diagnostic plus a new ecu and wiring harness $1500, we lost our shirt on this repair since we plugged in another ecu as part of diagnosis - zap it blew ours too. The tech though ours was bad so he tried another one, zap blew that one also!

A one of a kind never seen before problem can be an expensive learning tool!