Check AT Light

[94J30]

I have had a flashing AT light since I bought the J a couple of months ago. I took it in to Nissan for a Diagnostic on the VTC system and had them check the AT light as well. They said it was the Vehicle Speed sensor code. Taking there word for it I just changed the sensor today and guess what. . . Check AT light. A little irritated I did the self diagnostic and got a "Line pressure solenoid" error code. What is this and how do I fix it??

[94J30]

I have had a flashing AT light since I bought the J a couple of months ago. I took it in to Nissan for a Diagnostic on the VTC system and had them check the AT light as well. They said it was the Vehicle Speed sensor code. Taking there word for it I just changed the sensor today and guess what. . . Check AT light. A little irritated I did the self diagnostic and got a "Line pressure solenoid" error code. What is this and how do I fix it??

Double checked it today and it was the 12th flash on the self diagnostic. . . Engine control circuit. How do I check this further and or repair this. I guess I should have also described what the J is doing. Well, basically it will shift hard from 1st to second gear around 3500-4000 rpms. It will also feel like it is changing back and forth from 3rd to OD at highway speeds. Any ideas?? A bad TPS would throw the Engine control circuit code wouldn't it?

Modified by 94J30 at 9:10 PM 12/24/2006
Modified by 94J30 at 3:50 PM 12/25/2006

[yodawill2000]

Hard shift from 1st to 2nd is normal till it warms up , Should smooth out after a few minutes.The back and forth thing is an issue.Somebody here will surely know the fix, gots many a guru!!

[94J30]

It is normal for it to stay in first till like 3500-4000 rpms at part throttle?? And then shift into 2nd??

[yodawill2000]

sounds pretty high.When I said Hard shift I meant it doesnt slip into 2nd , It goes to second with a kick!

[94J30]

It does go into second with a crisp kick. Well, out of curiosity, I dropped the Trans Pan and changed the filter. I am not sure if it had ever been done before. The gasket flaked off the pan. The oil was dirty but not burnt. I think it was the dirtiest Trans Pan I have ever seen. Lots of varnish and gunk in the pan. After a thorough cleaning of the pan, magnet and double checking all the connections of the connectors I filled her up with fresh fluid and it no longer shifts into 2nd as high in the RPM range or shift in and out of Drive to 3rd at highway speeds. It does however feel like the 2nd to 3rd shift is a little soft or slow. Just a simple fluid change made tons of difference. I am going to reset the computer in a couple minutes and we'll see what happens. If the AT light is still flashing and I'm sure it will be, I'm back to square one with either a line pressure solenoid or engine control circuit error or both.

[yodawill2000]

Just dropping the pan only drains about 3 quarts. Did you fill it , run through the gears , drain and fill a few times ??

[94J30]

Just dropping the pan only drains about 3 quarts. Did you fill it , run through the gears , drain and fill a few times ??

I will be draining it again tomorrow. I actually had over a gallon of fluid come out the pan. And it wasn't overfull.

[95-J30tt]

is the AT light still blinking ???

i had an issue with the AT light once, it blinked for few seconds after startup, after checking everything, it turned out to be one of the wires that hook up to the transmission were not hooked up (i took the transmission out and put it back in right before this happened)

do you have a problem with the speedometer not reading correctly or the RPM jumping around when you accelerate??, the transmission light would blink on startup if either the speed or RPM sensors fail..... hope this helps, good luck, please keep us updated

[94J30]

is the AT light still blinking ???

i had an issue with the AT light once, it blinked for few seconds after startup, after checking everything, it turned out to be one of the wires that hook up to the transmission were not hooked up (i took the transmission out and put it back in right before this happened)

do you have a problem with the speedometer not reading correctly or the RPM jumping around when you accelerate??, the transmission light would blink on startup if either the speed or RPM sensors fail..... hope this helps, good luck, please keep us updated

The AT light is still blinking. All the connections on the tailshaft of the transmission are good. The Speed Sensor is brand new( thats the code nissan said it threw)

Speedo is fine, even with the old speed sensor, RPMs are stable and never erratic.

[luchador]

hey dude, i have the same problem,identical.iam going to drop the pan also to see if that helps.this started when i let my brother use my car one day. He said he was reving the engine to see how strong the engine sounds, and he accidently shifted into reverse!!!!!!!!! iwas pissed off!after that the transmission would just run on 3rd gear, but the next day it was back to normal except for one thing, 2nd gear!!! 1st gear works fine but it takes a while for the 2 gear to kick in, at about 4000 rpms. and just like your car, when driving on the highway, it feels like its switching in and out of gears ! going to check with obd. does anyone know what could be the problem,i hope its not my transmission!!!! by the way, this the best and most helpfull forum out there. thanks to every one that shares their knowledge and experiences on the j30!!

[94J30]

hey dude, i have the same problem,identical.iam going to drop the pan also to see if that helps.this started when i let my brother use my car one day. He said he was reving the engine to see how strong the engine sounds, and he accidently shifted into reverse!!!!!!!!! iwas pissed off!after that the transmission would just run on 3rd gear, but the next day it was back to normal except for one thing, 2nd gear!!! 1st gear works fine but it takes a while for the 2 gear to kick in, at about 4000 rpms. and just like your car, when driving on the highway, it feels like its switching in and out of gears ! going to check with obd. does anyone know what could be the problem,i hope its not my transmission!!!! by the way, this the best and most helpfull forum out there. thanks to every one that shares their knowledge and experiences on the j30!!

The fluid and filter change does appear to help smooth out the first to second shift. It also lowered the RPMS it would shift into second gear by 500 or so. Mine had an extremely dirty pan and filter. If yours has sludge and varnish in there a few quarts of fresh fluid will help. But like YodaWill said, there will be much fluid still in the transmission, torque convertor etc. I personally was able to drain a four and a half qts of fluid out of the pan. It was on jackstands pretty high though.

[94J30]

[QUOTE=94J30]

Double checked it today and it was the 12th flash on the self diagnostic. . . Engine control circuit. How do I check this further and or repair this. I guess I should have also described what the J is doing. Well, basically it will shift hard from 1st to second gear around 3500-4000 rpms. It will also feel like it is changing back and forth from 3rd to OD at highway speeds. Any ideas?? A bad TPS would throw the Engine control circuit code wouldn't it

OK, so after cleaning the pan and installing a new filter and 4 1/2 qts of fluid it is shifting smoother. I do however have 2 error codes. Revolution sensor and Engine control circuit. I can change the revolution sensor but the engine control circuit has me clueless.