04 NISSAN SENTRA 2.5 lack of power drive by wire.

God bless you my brothers and sisters.
It's back I get another chance to try and fix this the last time it came in was Jan.2019. OK here we go car came in with the same problem no power and this time it stalls I think it's because it's in fail safe mode. Here are the codes I get p1121, p0223, p0123 and p2135 they all relate to the t/b. The last time I replaced the t/b and it did no differences at least to me. The customer said that to her it was better but knew it was not a fix. She has taken it to other mechanics but know one has fixed it.
The car accelerates fine at idle but not in gear I checked the wires from pedal to ecm and from t/b to ecm all good. As I was checking the pedal for glitches and stepping on the pedal I heard a noise in the trans. That to me did not sound normal so I dropped the pan and found that the line pressure solenoid vale was the cause of the noise. When I stepped on the pedal about 1/2 way this solenoid will start clicking and gets hot fast. Question here is will this cause the t/b codes I'm getting. All help welcomed and Thank you.
STAY SAFE OUT THERE BROTHERS AND SISTERS.

God bless you my brothers and sisters.
Monde thank you for your respond, does this still happen with the engine off? There is no pressure at that time, I'm I activating this by stepping on the pedal.
Thank you.

Gilbert! Great to see you.

I have a hard time seeing those being connected, TBH. Pretty sure these use a separate TCM for trans functions.

Refresh my memory - what parts have been changed on this vehicle? Besides the TB.

God bless you my brothers and sisters.
Hey Tyler the only thing beside the t/b was a speed sensor that a friend of a friend said to do. The other guys that checked this car out just took her money.

Here is a pic of the APP I was checking was hooked up at the ecm. White wire and red and black.
Sorry for the poor quality it's all I have.

Thank you my brother but is it still normal for this to happen. That the solenoid activates with the pedal 1/2 way down. Did I in some way activate by stepping on the pedal over and over. You know now a days you can do some way out things by stepping on pedals. LOL

Is in fail safe mode, as in while trying to drive, it won't go over 5mph and has almost zero throttle input?

Makes me wonder if the cvt is shot. There is a tcm update that enhances the dtc logic, and displays codes that it won't before you get the updated software loaded.

I haven't looked up the code descriptions that you have but for some reason I feel like there might be TB codes in limp mode just because it limits the throttle opening and uses default values. I might have made all of that up though, ha. Not the throttle opening though, that's real.

Monde, does this sound familiar to you? The cvt failures are so freaking common that if there is a limp mode situation, the service writers put that line on the RO as Trans diag. ha.

It would be good to see if the tsb applies to this vehicle and check the TCM to see if the # is on the bulletin list of updates. IF this is on track at all that is.



Nissan Technician

Cripes, sorry. I see that it's a 2004. I thought it was newer for some reason.

Nissan Technician

Ok, I just looked up the codes. When you were testing the throttle body wiring before, was the problem currently happening? Hopefully it is happening right now for you. I would check the green wire for an open. Scan data would probably show 5v on TB sensor 2 if it's open but I'd probably use a meter in case scan data isn't accurate in fail safe mode. It's the green wire on the sensor. It could be intermittent, and would explain why the new TB didn't fix it too. Key on, foot of the throttle should be less than 4.75v on there (possibly more than .36v since it could be just an inversion of TPS1).

Nissan Technician

Ok, I just looked up the codes. When you were testing the throttle body wiring before, was the problem currently happening? Hopefully it is happening right now for you. I would check all of the wires at the TB again, if it is currently malfunctioning. It could be intermittent, and would explain why the new TB didn't fix it too. If you want to use scan data, there are two TB sensors. Key on, foot off the throttle should be less than 4.75v on one and more than .35v on the other. At full throttle the two sensors swap voltages. 5v or 0v on either would be a short to ground or open. You can graph them and look for a smooth transition with no drop outs, which I think you said you did. Maybe only look at one at a time for fastest scantool data refresh.

Also recheck powers and grounds since they both share the same ones. Key on, you need near battery voltage on power and less than .1v on ground.

Code descriptions for those of you following along are P0123 TP Sensor, P1121 Electronic Throttle Control Actuator, P0223 TP Sensor, P2135 TP Sensor.



Nissan Technician

gilbert wrote: God bless you my brothers and sisters.
Hey Tyler the only thing beside the t/b was a speed sensor that a friend of a friend said to do. The other guys that checked this car out just took her money.

I thought some wires had been overlayed? :huh: My mistake.

Has the TP sensor connector been checked for pin fitment? Spread pins and the like. From someone monkeying around before you got to it.

God bless you my brothers and sisters,
Tutti57 the problem is there when it's in gear, in park or neutral it revs fine. That is the reason I said lack of power maybe I should of said no rpm past 1000 in gear. I will do thees test on Monday but with the pedal working does it mean in park and neutral doesn't that mean wires or ok. I will recheck everything and see if anything differs from your specks.
Thank you.

God bless you my brothers and sisters.
Tyler I did fined a spread connector but the problem is still there after the fix.

Have you done the Accelerator Pedal Released Position Learning and Throttle Valve Closed Position Learning procedures? Page 47 at www.nicoclub.com/service-manual?fsm=Sentra/2004/ec.pdf

Jreardon I have done the idle relearn and no change. Thank you

God bless you my brothers and sisters.
Mr. Tutti57 BLK. wire 5.8 v ,GRN. wire in park 4.37v pedal released pedal down 4.32v, GRN wire in gear 4.37v released and 1.0v down. Wht. wire in park .79mv released and down .79mv in gear 4.16v down and .74mv released.

God bless you my brothers and sisters.
Monde the throttle does not open with key on engine off and in park. Is this normal, it only open if it's in gear .

God bless you my brothers and sisters.
Monde sorry I haven't been able to get to it had other work that need to get out. I'll try tomorrow to get to that APP first thing in the morning thank you for keeping up on the post.

God bless you my brother's and sisters.
Monde here are the the readings from the wire's red/yel 5.08 v released and down.
Red wire the same 5.08 released and down, what wire 0.773 released and down 4.58 v.
Blk/yel 013.9mv released and 015.5mv down, grn wire 014.5 mv released and 015.9mv down
and red/blk 0.394v released and 2.300v down. The pic are we with the pedal down thank you.

God bless you my brothers and sisters.
Hey Monde if it's not to much to ask can you put up some pic's of your tps and APP sensor readings. My scope does not have zoom so i don't know if I'm getting noise or drops. If you can put it at the lowest setting so that I can have some idea of what it should look like. Thank you