2002 4Runner sudden deseleration

[gs300tt]

On my 2002 4Runner I am having a re-occurring problem while driving at a constant speed and pedal pressure the vehicle suddenly decelerates and you have to apply more pedal pressure. I had this same problem over a year ago and replaced the throttle body to resolve it, but it is now occurring again. I am about 99% sure it is the Accelerator Pedal Position sensor on the throttle body which cannot be purchased by itself.

Has anyone else experienced this problem on a 2001-2002 4runner and if so what was the solution? I do not want to keep buying used throttle bodies just to have them fail in a year.

 

[BlackCat914]

On my 2002 4Runner I am having a re-occurring problem while driving at a constant speed and pedal pressure the vehicle suddenly decelerates and you have to apply more pedal pressure. I had this same problem over a year ago and replaced the throttle body to resolve it, but it is now occurring again. I am about 99% sure it is the Accelerator Pedal Position sensor on the throttle body which cannot be purchased by itself.

Has anyone else experienced this problem on a 2001-2002 4runner and if so what was the solution? I do not want to keep buying used throttle bodies just to have them fail in a year.

I bolded the problem. If you don't want to deal with reoccurring issues, don't buy used parts.

 

[gs300tt]

I bolded the problem. If you don't want to deal with reoccurring issues, don't buy used parts.

Thanks for the help I will run out and buy the $1200 throttle body now.

 

[Brian757]

Thanks for the help I will run out and buy the $1200 throttle body now.

Throttle Position Sensor (Aftermarket @ ~$40)
Throttle Position Sensor (OEM @ ~$45) (Scroll Down to Bottom)
Done.

 

[Singtoe]

Sounds like a drinking problem to me.

 

[gs300tt]

Throttle Position Sensor (Aftermarket @ ~$40)
Throttle Position Sensor (OEM @ ~$45) (Scroll Down to Bottom)
Done.

Thank you for looking that up but I am looking for an Accelerator Pedal Position sensor not a TPS. They are two different things and only came on the 2001-2002 years of the third gen 4runners. I guess what I really want to know is if anyone with a 2001-2001 runner has experienced a similar problem?

 

[brian4t]

Thank you for looking that up but I am looking for an Accelerator Pedal Position sensor not a TPS. They are two different things and only came on the 2001-2002 years of the third gen 4runners. I guess what I really want to know is if anyone with a 2001-2001 runner has experienced a similar problem?

2001 with 130k here and never had it. Aside from a sensor problem have you investigated a wiring / ground problem with the sensor itself? Can get pretty hot under the hood. I just had to replace all my vacuum hoses, our runners are getting up in age.

 

[BlackCat914]

Thanks for the help I will run out and buy the $1200 throttle body now.

It took 15 seconds to google it. $1,200?
2001 Toyota 4runner Used Throttle Body (Genuine OEM Quality)

 

[Brian757]

Thank you for looking that up but I am looking for an Accelerator Pedal Position sensor not a TPS. They are two different things and only came on the 2001-2002 years of the third gen 4runners. I guess what I really want to know is if anyone with a 2001-2001 runner has experienced a similar problem?

Ah, I gotcha. Misread you. I have an '02 but have not experienced this issue.

It took 15 seconds to google it. $1,200?
2001 Toyota 4runner Used Throttle Body (Genuine OEM Quality)

That is a used throttle body. He was referring to a new one. Still a little high, but they're expensive.

 

[asahi4runner]

Just replace one for my friend it was only $395

 

[gs300tt]

It took 15 seconds to google it. $1,200?
2001 Toyota 4runner Used Throttle Body (Genuine OEM Quality)

Look man I am trying real hard not to be a dick here. I am more than capable of finding a used throttle body but I have been down that road. I am trying to determine if this is a chronic issue or I just had bad luck with two throttle bodies.

 

[gs300tt]

Just replace one for my friend it was only $395

Why was it replaced? What were the symptoms?

 

[asahi4runner]

I really don't know the exact symptom he had it diagnosed at the dealership and they wanted to charge him an arm and leg. So he found one online and I installed it for him.

 

[BlackCat914]

Ah, I gotcha. Misread you. I have an '02 but have not experienced this issue.



That is a used throttle body. He was referring to a new one. Still a little high, but they're expensive.

ya, it's a re-manned, but at least it has a warranty and is 1/3 the price of a new one.

 

[BlackCat914]

Look man I am trying real hard not to be a dick here. I am more than capable of finding a used throttle body but I have been down that road. I am trying to determine if this is a chronic issue or I just had bad luck with two throttle bodies.

I think if you get to the point where you're replacing two of the same parts in a short amount of time, there's other issues going on. A quick forum search reveals that while it doesn't appear to be common, there are a few others that have had issues.

 

[gs300tt]

So I determined 100% that the problem was the Accelerator position pedal sensor (APPS) by driving the truck and when I experience the problem I would turn on Cruse Control and the problem went away. So I took apart the APPS of my original throttle body that I swapped out a year ago to see what I was dealing with. Below is a picture of the insides I took more but my phone messed them up some how.

You can see it is a very basic circuit board and on the back (not pictured) there are two sets of traces that are connected by a jumper with two fingers that ride along them. This unit has experienced the same symptoms but I saw no visible signs of damage on the traces or the fingers.

So with this knowledge I went to a friend’s shop to see what could be done. On the 15 minutes of highway driving to get there the acceleration dropped out 10-12 times. I took the APPS off the car and used electrical contact cleaner to clean the insides. There is a small hole in the back cover of the APPS but it was not large enough to get adequate cleaner through. So I carefully drilled a larger hole outside the area where the traces where on the circuit board below. I then flooded it with cleaner and actuated the mechanism to move the fingers. I shook out all the excess cleaner and blew it out a bit with low pressure air.

At this point I would not go so far as to say it is fixed but on the drive home and drive to work this morning it did not mess up. I am going to remove it again tonight and fill the hole with RTV or epoxy to reseal it.

Thanks to everyone for your suggestions and I will follow up if the problem returns.

 

[gs300tt]

I think if you get to the point where you're replacing two of the same parts in a short amount of time, there's other issues going on. A quick forum search reveals that while it doesn't appear to be common, there are a few others that have had issues.

I was able to find some good information on TTORA and it apears to be a bigger problem with the Tacomas. Here is the link if anyone is interested.

Accelerator Pedal Position Sensor & Throttle Control Motor Don't Turn Together? - TTORA Forum