mikemc12

Hey CL

I was driving the down the road and suddenly had my dashboard light up with CEL, VSC, and ABS lights, took it to a mechanic, he scanned P2111 Throttle Actuator fault, flap unable to close.

The car is in limp mode, and I definitely felt the surging RPM when idling and also in gear. I also recalled that in the weeks leading up, I've had experiences when lifting off throttle, the car maintained speeds going over level ground, which is in line with the issue at hand.

Going through the forums, I guess there are a few ways which this problem could potentially be solved:
1. Cleaning the throttle body and MAF sensors
2. Replace the throttle body (expensive)
3. Replace the ECM (even more expensive)

With the previous experience of the car maintaining speed after lifting off throttle, I would think that it was a gradual failure, not a sudden failure of the flaps, would that mean that it's more likely a dirt buildup issue with a sensor/throttle body as opposed to a mechanical throttle body failure (that would most likely be sudden?), which would warrant a replacement throttle body.

I am not very mechanically inclined, so I would need to have a mechanic help me with the work needed. There are ways I could do this:

1. The current mechanic, who is saying he would charge me $200 labor plus part (which I could source myself potentially). His shop is really busy and didn't charge me a diagnosis fee, he said that he didn't have time to do a full diagnosis (he checked the wires for the throttle body and he said that they look fine), so he is saying to just swap the throttle body, and see if that fixes the issue.

2. I could tow it to another mechanic, who specializes in LC and other Toyota trucks, very knowledgable on Toyota products. He said he could clean the throttle body and MAF sensor for around $100 in labor, and see if that would fix it. Otherwise he can replace the part for around $300 plus the part that either he or I source, can probably talk him down to around $250 potentially.

3. Taking it to a Lexus Dealer or another Lexus specialist, would probably cost around $100-$200 for a diagnostic fee, I wonder if scanning with Techstream would help pinpoint the issue, (mechanical? connections? dirty sensors?). The dealer would probably charge an arm and a leg to fix it, but I have read in another CL post that a GX460 owner had dealers diagnose a loose connection and saved him thousands in repairs.

I have a few questions, and I hope folks here on CL could help me out here:

1. I am inclined to take option 2, as I feel like a mechanical issue with the throttle body is fairly rare on the LS460, and replacement parts are expensive. I am wondering if I could get it cleaned first to see if it could be fixed.
2. Based on the fact that the issue gradually presented itself, I wonder if the problem is more of dirt buildup, or a loose connection, than part failure of the throttle body.
2. Would it be advisable to buy a used throttle body on eBay if I would need to replace it? The price difference is quite large ($150 vs $700).
3. Would techstream help at all at pinpointing the problem beyond code P2111? Would the diagnostic fee be worth it at the dealer or another Lexus specialist?

Sry for the essay, but it's a pretty rare problem for the LS AFAIK and I hope CL could give me some suggestions, thanks in advance!

Anfanger

Have you tried cleaning the throttle body?

mikemc12

I haven’t yet, as the first mechanic didn’t want to clean it, just replace the part.

I am leaning towards towing it to the 2nd mechanic that specializes in LCs and have him clean it.

Would techstream help at all and pinpointing the problem I wonder? It would require a diagnostic fee tho.

Anfanger

Techstream allows to activate the actuator. After throttle body cleaning, the software can be used to test the actuator which should help in deciding if it needs to be replaced. By the way, it is easy to damage the actuator during throttle body cleaning.

mikemc12

gotcha. Is techstream easy to use?

I could get it from eBay or aliexpress for a reasonable price it seems.

trogdor113

Techstream is easy to use, especially for this. It has the ability to manually actuate motors and the like, so you can see if the throttle is actually moving. The surging you described is the ECM attempting to regulate speed by cutting off fuel:

I agree with Anfanger; the throttle body isn't that hard to get to, and it's pretty apparent if it's not closing like it should. Cleaning it is pretty easy; just don't let the butterfly slam shut. Be aware though that it has coolant lines and passages, so complete removal from the engine bay will require draining at least some coolant.
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swfla

iTrader: (1)

Reluctance to paying a diagnostic fee is counterproductive. All modern cars use computers, using a program to read those computers is the best way to resolve an issue. Buying tech stream on eBay is not as simple as that. There are issues with connecting cables and incomplete software pirating. It's been discussed here many times, do some research.

Gerf

Yes, it would be pretty hard to start diagnosing some problems without a scan tool or ts but you have to know what you're looking at.
I've read quite a few posts where people have replaced the first part on the possible cause list and it wasn't the problem, I suppose that's better and cheaper than having a repair shop do the same thing.

Boykie

Uhm, just to butt in - in what universe using Techstream, internal pro toyota tech software, is easy? I mean to a person, asking where to take the car for TB cleaning? It may be somewhat easy to do health check, yes. But active tests? Heck no.

trogdor113

I'm admittedly a computer engineer by day, but it's not rocket science. I mean, we're talking about clicking some buttons in software. Not to insult any automotive technicians, but this stuff was literally written and designed for people who potentially have little education outside of working on their brand.

If all else fails, fall back to the "computer person" workflow (credit to XKCD #627):


I'm not a mechanic, but I've rebuilt engines and transmissions, replaced heater cores requiring entire dash removal, etc. No one starts knowing this stuff; you have to jump in at some point and figure it out as you go.

Protholl

Agreed about techstream. I've never been able to get a version that didn't have a virus embedded in it. It is pirated after all and the pirating tools being used actually add the virus payload.

trogdor113

While you can (and many do) use an illegitimate copy and a Chinese-made interface clone, that's not a given or required.

I think it's often forgotten or ignored that anyone can get access to the factory Lexus service information and software: https://techinfo.snapon.com/TIS/Register.aspx
$70 gets you 2 days of access to the service manual for any Lexus and use of Techstream from the source. This is literally required by law for any emissions-related ECU via the J2534 protocol; I personally use an Autel MaxiFlash Elite. The great thing about J2534 is that it's an industry standard so you can use it with any make. I can also reprogram and run diagnostics on my Ford.

The cost of an interface plus $70 per incident may initially seem steep, but all the dealerships (and good indy shops, for that matter) I know are charging $140 to $150 for labor, if not more. The investment quickly pays for itself. In my experience the dealer techs are only doing what the manual/software tells them to; why not cut out the middle man and save some money?

I'm not any smarter than any other guy or gal, my only advantage if any is that I'm willing to stick with it until I figure it out. If someone doesn't want to do the work because they don't have the time or don't think it's worth it, that's one thing. I hope no one is dissuaded from working on their own stuff because it's "too hard".

Protholl

Agreed but its rare that I actually have more than a day in a row to work on an issue... more like a few consecutive weekends 3 hours or so per problem so the $70 didn't work for me in my situation. FYI: I did pay for the real thing three times in the past few years. That was the reason I went with the knockoff. I also have an Autel 808BT which does most things but not as well as techstream which I have used recently to double-check the Autel.

mikemc12

Thanks for the advice guys!

I think the best course of action is just get it somewhere with TS, get them to scan it.

I just wonder if they would be able to fully diagnose the issue with TS in hand? Or is more of the same "I think it could be these problems, a, b and c, we will have to try them out one by one"....

Also, would it be better to just clean the TB and MAF first just to see if it would fix it, other than possibly damaging it? I do trust the 2nd mechanic though, and I think a cleaning wouldn't hurt anyway.

Boykie

Print this out and take with you.