Accelerator Pedal Position Sensor (APPS) replacement 2001 4Runner?

So, I'm getting a P1120 code which is associated with an APPS circuit. Initially I had a code that pointed toward the Throttle Position Sensor (TPS) as well. I replaced that but continue to get the P1120. Unfortunately (though it's a removable part) I cannot find an APPS without purchasing a whole new throttle body.

BTW...if I reset the codes the truck drives just fine until it senses something in the APPS (wrong voltage, I would assume) and trips the code again. There is really nothing else wrong with the throttle body. I've removed it, inspected and completely cleaned every part. No cracks, clogged air bypasses, etc.

Looking for any help. Thanks.

 

So...let me just say that for this throttle body that is on the 2001-2002 cars, for the LONGEST time, you couldn't even get the TPS. TOYOTA said it was a NON serviceable throttle body. While I think it's bogus that they don't supply parts for it, I kind of see their reasoning. That TB is COMPLICATED inside. Motors, gears, valves, sensors, etc. So they build it at the factory and set it up and it's done...no fiddling or adjustment. Just bolt it on.

I was having some TPS/Pedal Position Sensor/IAC codes thrown and finally caved and bought an ENTIRE throttle body from McGeorge Toyota for like $650.

Night and day difference in driveability.

Fixed:
High idle on startup.
Low idle on warm up.
Surging idle with AC on.
Hesitation in initial depressing of the accelerator.
Uneven acceleration.
Shifting
MPG
All those codes.

For me, it was the best money I could spend. She's a new car. Drives like she did 19 years ago.

After I did that, I found you can get the TPS. I don't think the Pedal Position Sensor (which I think you call the APPS) is available yet. I probably only needed a TPS. But she's my daily driver and she's kept me out of a car payment for 15 years...IMHO worth a new TB.

That being said...depending on your wallet, I would either buy a new TB or go and hunt down a used pedal position sensor (or two) out of a junker (or two) and whatever Tacoma had the same Throttle Body. Also check the Tacoma boards and see if they have located the sensor for sale.

 

Negusm,

Thanks. After all my research it would seem that the TPS and APPS have to be paired synched up voltage-wise (I'm inferring anyway), but I also think there is something wrong with the APPS. I do believe I'm just going to pony up the dough to buy a throttle body. I have found a new one for $450 (https://parts.rickhendricktoyotasan...GgLhlAvTQEg8KdSWojgrJ5aOSTwipNTRoCkyIQAvD_BwE).

I'm pretty confident this will fix the issue once and for all. When you swapped it out I'm assuming you just let the computer do it's thing and find it's new idle after warm up? Thanks again!

 

Make sure you have them use your VIN and verify that is the correct throttle body for you. If you open the box and it's wrong...they won't take it back. You will own a very expensive door stop! You don't want a running change for 2001 messing up your day.

$450 is a GREAT price. Like I said, I paid $650 and that was 30% off from the dealer MSRP! I think Toyota may be dropping prices on things, maybe they will stop stocking them soon.

And yes, you put it on (with a NEW gasket) and just let the computer learn for about 30 minutes. Idle will start high and then move into the 750 rpm range.

Clean your MAF while you're there so the computer gets the best inputs.

I don't think those sensors (TPS and PPS) have to be "matched". They are just big complicated variable resistors and the computer figures them out after a bit. If you just replace the TPS, you are supposed to adjust it by leaving the one screw on the side loose and then moving the TPS while the car is running until it gets in the 750 rpm range then tighten it in position. Even so, I bet the computer adjusts to wherever it is set.

 

I checked my order from McGeorge and I got part 2203062020 which matches yours. Also, this number SHOULD be on top of the old TB. Make sure it matches.

McGeorge also has it cheaper now: $436.37

 

I dont mean to Highjack your thread here, but I have been having this same issue for over 6 months now; and this is the only discussion I have found. I have replaced the TPS, ECM, as well as the full TB, and I am still getting the P1120 code. Now the TB was used, but it was in working condition when the guy put it away. Would you guys be able to shed any further light on this subject?

 

A used TB can still be suspect. If you read this, that code pretty much puts the blame on the Pedal Position Sensor or the ECU or the wiring in between.

If you can't buy a replacement PPS, maybe you can open one of yours up and clean the contacts really well.

Otherwise, if you are sure of the ECU and wiring, there's not much else that I know of to do but get a NEW TB from Toyota and eliminate that variable.

 

Thanks for the link. I might just put my original ecu back in and buy a new TB. I cleaned the contacts today, as well as the Mas, and that didn't help. This whole issue has really racked my brain.

 

I would verify your wiring. It does seem to be the one thing you haven't tried to fiddled with.

When you clear the code, do you get the code really soon after startup? If so, I'd think that it's maybe a break in the wiring.

Logically, the TPS and PPS don't usually completely fail. They just get sloppy as the internal contacts wear out. I would think that the code would pop up after driving for a random amount of time. Regardless, the contacts in the sensors at idle position will probably wear out first on all TPS and PPS because that's where they get the most use internally.

I'm not an expert on this thing, someone else may know better on how to troubleshoot.

 

Hi....On the off chance that you discovered the schematics for the 3 and 4 prong, ensured the 3 prong would squeeze into the choke body (situated on the back of the TB), and arranged the wires. That COULD work. I would prefer to take a risk on the 4 prong Supra TPS sincerely.

 

I have a 2002 4 runner 3.4 v6. I’ve replaced the 2 knock sensors with wire harness. I’ve also replaced the cracked air intake hose. This corrected my engine light. I still have a problem with acceleration especially wide open throttle. I scanned the TPS and it stops reading at about 77-79% and the engine won’t go. It just falls flat on its face. I believe the TPS is bad. What does everyone think??
Thanks,
BLB

 

Probably. Luckily you can get the correct TPS from PartsGeeek now as before the only option was to replace the entire Throttle Body.

 

Can Nash D or Totes give an update on their outcome? I'm dealing with similar problems now. Thanks a lot.