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2004 R50 Shifting Issues - Throttle Position Sensor?


KanyeFresh
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Hey all,

 

I brought in my 2004 Pathfinder (VQ35DE, auto transmission) to the shop today since I was having some issues with it recently. I was driving up a moderate hill and when it downshifts (from 4th to 3rd maybe?) when I'm going around 70-80km/h the transmission wont engage and the vehicle starts jerking while the rpms rapidly bounce back and forth. There are no grinding sounds, it just sounds like the vehicle cant pick a gear and is jumping back and forth really quickly. I have to left of the gas and then I'm stuck in that gear. It seems to only happen on hills and above 50km/h or when I'm accelerating somewhat hard. One thing to note (not sure if this is relevant or not) but last weekend I pushed the pathy pretty hard shuttling up and down a mountain while mountain biking. Not sure if the stress from hauling bikes up and down a fairly steep trail wore some thing out or not...

 

The mechanic said he's not certain but he thinks it's probably the throttle position sensor so he's ordering in a new one. 

 

I wasn't getting any engine lights or anything so I'm wondering if he picked up codes that pointed to this? Has anyone run into this issue before?

 

Thanks!

Edited by KanyeFresh
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TPS sounds like a reasonable guess. A code should've lit up the CEL, but he might've found a pending code or seen some indication through live data that the sensor was glitchy or had a dead spot or something. Hopefully the TPS fixes it.

 

My dad's '03 developed a weird bucking issue under load which felt like the throttle was snapping open and closed repeatedly. It was fairly violent. No check engine light, and I don't think it ever threw a code (I didn't have a scanner at the time, so I was going off what the mechanic told us). IIRC the mechanic he took it to replaced the swirl control valve control solenoid valve (seriously) and that fixed it. I have no idea what was wrong with it or why it made the truck lurch like it was trying to shake something off the roof rack. Looks like it's supposed to set a P1130 if that component goes bad, but I don't know what the computer checks for.

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12 hours ago, Slartibartfast said:

TPS sounds like a reasonable guess. A code should've lit up the CEL, but he might've found a pending code or seen some indication through live data that the sensor was glitchy or had a dead spot or something. Hopefully the TPS fixes it.

 

My dad's '03 developed a weird bucking issue under load which felt like the throttle was snapping open and closed repeatedly. It was fairly violent. No check engine light, and I don't think it ever threw a code (I didn't have a scanner at the time, so I was going off what the mechanic told us). IIRC the mechanic he took it to replaced the swirl control valve control solenoid valve (seriously) and that fixed it. I have no idea what was wrong with it or why it made the truck lurch like it was trying to shake something off the roof rack. Looks like it's supposed to set a P1130 if that component goes bad, but I don't know what the computer checks for.

 

Hmm, interesting. The way you described it sounds very similar to what I was experiencing.

 

Well hopefully, the TPS replacement fixes it otherwise perhaps it's the same issue.

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+1 for the TPS.

My TPS was worn on the spot where I cruised at highway speeds and that caused the trans to think I was accelerating for quick bursts which made the lockup solenoid flutter.


Sent from my iPhone using Tapatalk Pro

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04 should have throttle by wire. The TPS is built into the throttle body and not replaceable without replacing the entire throttle body if it is. Wonder if he is thinking the TPPS, the throttle pedal position sensor. I believe that they are the entire throttle pedal, but not sure with the early ones. Can check and see if the connector is tight and clean. 

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13 hours ago, Mr_Reverse said:

04 should have throttle by wire. The TPS is built into the throttle body and not replaceable without replacing the entire throttle body if it is. Wonder if he is thinking the TPPS, the throttle pedal position sensor. I believe that they are the entire throttle pedal, but not sure with the early ones. Can check and see if the connector is tight and clean. 

 

Interesting. Yeah, I just read through the Haynes manual and 2003 models and higher with the V6 have the TPS built-in. Not sure what he is planning to replace then. I was told it should be fixed sometime today so I'll post an update on what happened.

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Just as an update: like Mr_Reverse said, the throttle position sensor is fixed to the throttle body on 2003 V6s and up. The mechanic ended up replacing the whole throttle body with a salvaged one. Also had to do the throttle pedal relearn procedure. So far it seems to be driving fine now so hopefully that's all that the issue was. Still kind of annoying not being able to replace just the sensor - ended up costing me a bit over $500 CAD all in and that was for a used throttle body.

Edited by KanyeFresh
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That price sounds about average for a used TB installed. The throttle relearn process isn't hard, but does go faster and easier when you have a scan tool that can do it. 

 

Just for the record, a throttle relearn should be done anytime work is done involving the intake system right down to throttle body cleaning. Also, it is a good idea to either disconnect the battery or unplug the throttle body before cleaning or manually opening the throttle plate. Sometimes the motor drive or sensors can be damaged if done while there is any power in the electronics. 

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  • 2 weeks later...

Hey guys,

 

So that issue came back yesterday. Anytime I gave it some throttle enough to downshift and hit 3000 RPM the car would jerk and the RPMs would flutter. I posted on the NPORA facebook group a video. I also picked up a code reader and got 0507 and 1131 (swirl control valve). 

 

I followed what one of the commenters said and unplugged all the vacuum lines around the SCV and cleared them out. I noticed a little bit of white dust fly out of two of the hoses. I cleared the codes and took it for a drive and it no longer experiences those issues and the 1131 code is now gone. The 0507 code does reappear but I think the mechanic who looked at it first didnt do the relearn properly...

 

Anyways I'm happy it seems to be fixed for the time being...but also annoyed I wasted $500 on a new throttle body when it was really a 20 min fix.

 

 

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Now that you mention it, I remember finding a little white crap in the vac lines on my dad's '03, too. Looked kinda like salt. No idea what it was or how it got there, but good to hear that blowing it out cleared up the fault! Hopefully it stays gone.

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  • 2 months later...

Hi all,

 

To follow up on this, the issue ended up coming back a few days later. I guess clearing out that gunk was only a short term fix. Anyway, I ended up buying a new swirl control valve solenoid (14956-1P10A) from the dealer for about $100. Replacing it was quite easy and upon starting up the vehicle and going for a test drive, the issue was fixed. The 1131 code was gone but the 0507 one remained. I assumed the mechanic just didn't do the relearn properly. So obviously I was pissed that the mechanic didn't fix the issue and replaced the wrong thing meanwhile I ended up buying parts and fixing it myself. Not to mention  creating a high idle issue. I held off on the idle issue for a while but recently decided I should do something about it as the vehicle was idling around 1200rpm even after trying to do the relearn procedures and I think it was killing my gas mileage.

 

So, I caved a took it to a dealer to sort out all this crap once and for all. They told me that the throttle body was not installed correctly and was missing the gasket. They also said the bolts were stripped and may need to be replaced, making the job even more difficult. The diagnosis cost $200 and I was quoted $245 to replace the gasket. So in total this damn mechanic has costed me almost $900 fixing (and causing more issues with) the wrong thing while I end up fixing the initial problem in 20min with $100 worth of parts...

 

Going to contact the mechanic in the hopes they will cover some of these costs...?

 

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