Yet Another Limp Mode Thread! Adding some Info (1 Viewer)

[RyanArcane]

Hi all

Was researching into 200 series problems and the dreaded limp mode problem came up. I have referenced some threads and another website to illustrate the problem. Any update on a solution would be greatly appreciated.

So basically if I understand, on rare occasions some 200 series (varying model years nothing I could narrow down) get into Limp Mode - a combination of VSCtrac and VSC off lights, Malfunction, etc. I read on a couple of other threads and some of the problems were

1) battery related (2017): Limp mode advice -'17 LC
2) Evap cannister related (last post on this thread on 2013): 2019 200 LC Check Engine and Limp Mode this morning
3) Rodents chewing knock sensors and other wirings (if I'm right on a 2020 LandCruiser): 2019 200 LC Check Engine and Limp Mode this morning
4) Blown Transmission in this case (years vary if I'm not mistaken but mostly 2016 some early ones as well): 2017 Land Cruiser - Transmission Needs Replaced
5) In this case APPS, TPS( Thottle Position Sensor/Accelerator Pedal Position Sensor problems ) replaced (2009- 2011 model but didn't follow up) : Another Limp mode thread HELP!

Reading upon this I came across this Australian Website: Toyota LandCruiser 2016:

Summarizing: Limp mode came on and put occupants in distressing predicament but someone commented that there are three common issues that they think cause this

1) faulty stepper motor associated with throttle body
2) faluly EGR valve
3) faulty accelerator pedal elecronics


I tried to be as comprehensive in my research as possible but this is not a complete list. However can experienced users please comment on the stepper motor, EGR valve and accelerator pedal issues along with APPS & TPS replacements. I think there is a trend here. Thank you for patiently reading through this and any response is appreciated. Just trying to compile for people who experience this in the future while I miss my 100 (in the garage with broken brake lines ) Thanks in advance!

 

[TeCKis300]

Not sure what you're trying to figure out? I'm guessing but are you suggesting there may be some systemic issue inherent in the 200-series that is a cause for limp mode?

Limp mode is a failsafe mode in all modern cars. It's a feature and safety function of the engine computer and can also be interpreted as safe mode. Any number of issues and permutation of issues can cause limp mode. Ultimately, the ECU is seeing something that is a mechanical or an electrical problem, that is indicative or an actual safety or mechanical critical issue, that it reverts to this behavior such that the driver can still reach someplace without potentially further degrading the vehicle and leaving occupants stranded.

For as long as I've owned my 200-series, and have been on these boards, I'm not aware of anything systemic in this model that causes limp mode. Every one of the cases you've listed are rare. Or can happen to any modern car. Including your 100-series.

 

[empty80]

Here’s another data point for battery and charging systems:

I installed an HKB Electonics diode yesterday. Diodes are polar, but there was no way to which side was which. The instructions indicated this as well. Attempt 1 installed backwards and triggered limp mode. The diode interrupted the charging circuit, so the battery likely would not charge. Attempt 2 everything was normal, codes cleared.

 

[CharlieS]

You get a battery light in the dash that does not turn off if you put the HKB diode in backwards. I'm reading the instructions to mine right now and it says this. I'd post it, if it didn't have a giant copyright mark across the page.

 

[empty80]

You get a battery light in the dash that does not turn off if you put the HKB diode in backwards. I'm reading the instructions to mine right now and it says this. I'd post it, if it didn't have a giant copyright mark across the page.

No dispute according to the instructions. I’m reporting what actually happened.

 

[CharlieS]

As am I. I put mine in backwards originally, got the battery light, turned the vehicle off, flipped the fuse/diode, and all has been good for many thousands of miles.

I guess my underlying thought was that you should see this before you drive a foot, and be able to fix it, so you'd never see "limp mode".

 

[Sandroad]

No dispute according to the instructions. I’m reporting what actually happened.

Not a valid data point. User error.

 

[Sandroad]

I agree with @TeCKis300 on the question of thread premise. I've been on the board almost since release of the 200s and limp mode is so rare that it doesn't seem quite right to title a thread "Yet another limp mode thread". And it doesn't seem quite right to use the phrase "....three common issues....." to describe some rare instances of failures. And, the Aussie web site may refer to LCs with different specs (diesel, 4.6L, etc) than U.S. spec. I know there are many members in other countries on here, so that may be valid for Australia spec trucks. Anyway, it will be interesting to see if you do find a trend that might lead to PM.

 

[empty80]

Not a valid data point. User error.

Are you sure about that? There’s only two ways to use a diode, right and wrong. Instructions indicate if installed backwards you’ll get a lamp indicating a battery issue. I got the lamp, but the truck was also went into limp mode. I flipped the diode around, and all was good.

The IMPLIED data point is, a system charging error (alternator, battery, ALT-S fuse) may trigger limp mode.

 

[RyanArcane]

I would still consider that a valid data point, more like this can lead to a Limp Mode issue (within reasonable margins of expected human error). This is mostly for documentation purposes. Do you happen to have pictures from the installation. Thanks!

 

[RyanArcane]

I agree with @TeCKis300 on the question of thread premise. I've been on the board almost since release of the 200s and limp mode is so rare that it doesn't seem quite right to title a thread "Yet another limp mode thread". And it doesn't seem quite right to use the phrase "....three common issues....." to describe some rare instances of failures. And, the Aussie web site may refer to LCs with different specs (diesel, 4.6L, etc) than U.S. spec. I know there are many members in other countries on here, so that may be valid for Australia spec trucks. Anyway, it will be interesting to see if you do find a trend that might lead to PM.

You're right the title is somewhat misleading since I didn't actually have another case of Limp Mode (will edit), I think my intention was to compile data points and try to corroborate something that is still a bit of a stretch. I think my initial intention was to followup on the Australian websites post about the acceleration pedal circuit and to see whether it was relatable to the APPS/TPS and possibly Throttle Motor Control. I haven't read anything about the EGR valve. I would also like to highlight the fact that this is one of those 'Appeal to The Extreme' cases but just to see whether there is an actual design flaw which manifests in rare cases or are these just related to faulty parts failing (which would be still pretty rare but could be addressed as QC issue).

 

[TacomaLC]

I was on the freeway and had a 2 Year old Honda Pilot go into "limp mode", RPMs wouldn't go above 3000 and vehicle speed <40mph. I had no idea what was going on. Took it to the dealer, turns out an oil pressure sensor had failed.

So, I would guess many sensor failures could cause "limp" mode.

 

[TeCKis300]

You're right the title is somewhat misleading since I didn't actually have another case of Limp Mode (will edit), I think my intention was to compile data points and try to corroborate something that is still a bit of a stretch. I think my initial intention was to followup on the Australian websites post about the acceleration pedal circuit and to see whether it was relatable to the APPS/TPS and possibly Throttle Motor Control. I haven't read anything about the EGR valve. I would also like to highlight the fact that this is one of those 'Appeal to The Extreme' cases but just to see whether there is an actual design flaw which manifests in rare cases or are these just related to faulty parts failing (which would be still pretty rare but could be addressed as QC issue).

No problem and it may be useful for someone that experiences the issue. Yet limp mode is incredibly broad and hard to diagnose based on the ECU being in that mode alone. Really need to pull codes to begin the debugging process.

APPS/TPS and throttle motor control potential for faults has been a thing since the inception of throttle by wire in the 90s. As a fault in throttle control is obviously a safety issue, the potential to trip limp mode from this subsystem is likely. Doesn't mean the 200-series is any more susceptible. I'd argue to the contrary as being a 200-series, Toyota design, and world class build quality, would make for a more robust system than average.