VSC and VSC Off Lights - Limp Mode
02-28-12, 08:16 AM
#181
Lead Lap
Thread Starter
Exactly, the Accelerator pedal sensor is completely different than the Throttle Position Sensor. And Lexus dealers WONT replace the accel pedal sensor...they will only replace the TPS or the entire Throttle Body.
I think Taunvilles suggestion about testing the Accelerator Pedal sensor is a good idea before replacing. I believe I tested mine before doing the Throttle Motor. Its been a while. Its a variable resistor, so it changes resistance as you turn the lever. I guess its possible once they heat up it starts shorting.
I think Taunvilles suggestion about testing the Accelerator Pedal sensor is a good idea before replacing. I believe I tested mine before doing the Throttle Motor. Its been a while. Its a variable resistor, so it changes resistance as you turn the lever. I guess its possible once they heat up it starts shorting.
dave, what I was getting at was the posts above went through all these situations where the OBDII readings indicated a TPS problem (1120, 1121 codes), then that did not fix the same 'limp mode' problem, then the problem was identified as the TCM (in my case, an 1128 code). And that did not correct the problem.
I saw above the throttle lever assembly corrected the common problem we all seem to be having. BUT, I see from your post I missed the "sensor" part of the Throttle Lever Assembly.
I see that part of the mechanical, cable driven unit on the rear of the throttle body is named "Accelerator Pedal Position Sensor". Which is different from the "Throttle Position Sensor" that is on the front of the throttle body.
I think I'm getting it now, dave. I think if I have the problem again, it's in abeyance right now, I'll go the that Throttle Lever Assembly as the fix.
I don't see an OBDII code for that, so it's not surprising it was a bastard to diagnose.
I saw above the throttle lever assembly corrected the common problem we all seem to be having. BUT, I see from your post I missed the "sensor" part of the Throttle Lever Assembly.
I see that part of the mechanical, cable driven unit on the rear of the throttle body is named "Accelerator Pedal Position Sensor". Which is different from the "Throttle Position Sensor" that is on the front of the throttle body.
I think I'm getting it now, dave. I think if I have the problem again, it's in abeyance right now, I'll go the that Throttle Lever Assembly as the fix.
I don't see an OBDII code for that, so it's not surprising it was a bastard to diagnose.
02-28-12, 08:18 AM
#182
Lead Lap
Thread Starter
02-28-12, 09:28 AM
#183
Unfortunately.... No. I believe VVT is the one who is waiting if the problem would recur. I'm te one waiting to get back to California to test the vsc system. Won't be back until July...
That's a bit odd how they won't change the APS.
That's a bit odd how they won't change the APS.
02-28-12, 12:16 PM
#184
Lead Lap
Thread Starter
They claim the Throttle Body is a factory assembly. When I told them I would do it myself they even tried telling me it might foul up the ECU because the sensors are "electronic"
Complete Malarky! Its a variable resistor, not a computer!
I have another Lexus too...Ive encountered the same BS service approach on it too. Lexus dealers want to make big bucks, and they assume lexus owners dont know jack about mechanics, and more so, they rely on the fact Lexus is a higher-end vehicle, so the owners are busy with jobs and dont want to get their hands dirty.
Its pretty sad if you ask me...Lexus should address the issue, but I doubt they will. Cadilac is also notorious for similar issues. And Id suspect so is BMW, Mecedes, etc...any of the higher-end dealers want to maintain a sophiticated appearance.
Snobs if you will :-)
Complete Malarky! Its a variable resistor, not a computer!
I have another Lexus too...Ive encountered the same BS service approach on it too. Lexus dealers want to make big bucks, and they assume lexus owners dont know jack about mechanics, and more so, they rely on the fact Lexus is a higher-end vehicle, so the owners are busy with jobs and dont want to get their hands dirty.
Its pretty sad if you ask me...Lexus should address the issue, but I doubt they will. Cadilac is also notorious for similar issues. And Id suspect so is BMW, Mecedes, etc...any of the higher-end dealers want to maintain a sophiticated appearance.
Snobs if you will :-)
02-29-12, 10:29 AM
#186
Lead Lap
Thread Starter
There ya go! I did the throttle-motor based on the Dealer telling me the accelerator sensor was "Electronic" and may not work with the ECU. That was before I took the rest of the used TB apart, a well as the accel pedal sensor only to discover its simply a variable resistor! HAHA
Any event, yes, I would recommend just swapping out the entire TB in future fixes if it ends up being the Accel Pedeal sensor (lever assembly) or the throttle motor...about the same amount on time, and get more "new/used" parts.
Any event, yes, I would recommend just swapping out the entire TB in future fixes if it ends up being the Accel Pedeal sensor (lever assembly) or the throttle motor...about the same amount on time, and get more "new/used" parts.
02-29-12, 01:03 PM
#188
Lead Lap
Thread Starter
When you say it was the throttle body itself, what part of it?
The TB itself is a cast-aluminum frame that everything bolts to. Has a water-port for pre-heating in winter. Basically got the throttle butterfly valve is supported by 2 bushings on each end of the shaft pressed into the TB housing. That shaft has a gear on the back-side of it, which has another larger gear mounted on a press-fitted bushing which the actual Throttle Motor drives. The Throttle motor screws onto the TB housing.
Did your TB get corroded or bent or did the bushings seize-up or something? Its actually a very simple assembly aside from the complex routing of sensors and signals to and from the ECU.
Just curious if you know what went bad with the actual TB housing itself. Thanks! Im sure someone will want that one you have.
The TB itself is a cast-aluminum frame that everything bolts to. Has a water-port for pre-heating in winter. Basically got the throttle butterfly valve is supported by 2 bushings on each end of the shaft pressed into the TB housing. That shaft has a gear on the back-side of it, which has another larger gear mounted on a press-fitted bushing which the actual Throttle Motor drives. The Throttle motor screws onto the TB housing.
Did your TB get corroded or bent or did the bushings seize-up or something? Its actually a very simple assembly aside from the complex routing of sensors and signals to and from the ECU.
Just curious if you know what went bad with the actual TB housing itself. Thanks! Im sure someone will want that one you have.
03-01-12, 04:05 PM
#189
honestly i dont know .. i know i had all 3 new sensors installed on my old throttle body ! and problem continued..
i purchased a throttle body with sensors installed and it worked fine so i went and replaced the sensors with the new ones and it worked fine also.. so i put the old sensors back on and tried returning the sensors but couldnt sold some of them here .. only have the throttle control motor left.. what i assumed was the mechanism inside the throttle body itself was off sync idk lol it was a shot in the dark ! and my last resort ! and it worked
i purchased a throttle body with sensors installed and it worked fine so i went and replaced the sensors with the new ones and it worked fine also.. so i put the old sensors back on and tried returning the sensors but couldnt sold some of them here .. only have the throttle control motor left.. what i assumed was the mechanism inside the throttle body itself was off sync idk lol it was a shot in the dark ! and my last resort ! and it worked
03-04-12, 04:42 AM
#190
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I dont think it will start, each key has an RF chip in it.
As for exchanging the ABS/VSC module, why did you do that before looking at the sensors on the TB? I know Taunville was going to try that, but thats because he already swapped the entire TB and didnt fix the problem.
As for exchanging the ABS/VSC module, why did you do that before looking at the sensors on the TB? I know Taunville was going to try that, but thats because he already swapped the entire TB and didnt fix the problem.
03-04-12, 10:16 AM
#192
dave, what I was getting at was the posts above went through all these situations where the OBDII readings indicated a TPS problem (1120, 1121 codes), then that did not fix the same 'limp mode' problem, then the problem was identified as the TCM (in my case, an 1128 code). And that did not correct the problem.
I saw above the throttle lever assembly corrected the common problem we all seem to be having. BUT, I see from your post I missed the "sensor" part of the Throttle Lever Assembly.
I see that part of the mechanical, cable driven unit on the rear of the throttle body is named "Accelerator Pedal Position Sensor". Which is different from the "Throttle Position Sensor" that is on the front of the throttle body.
I think I'm getting it now, dave. I think if I have the problem again, it's in abeyance right now, I'll go the that Throttle Lever Assembly as the fix.
I don't see an OBDII code for that, so it's not surprising it was a bastard to diagnose.
I saw above the throttle lever assembly corrected the common problem we all seem to be having. BUT, I see from your post I missed the "sensor" part of the Throttle Lever Assembly.
I see that part of the mechanical, cable driven unit on the rear of the throttle body is named "Accelerator Pedal Position Sensor". Which is different from the "Throttle Position Sensor" that is on the front of the throttle body.
I think I'm getting it now, dave. I think if I have the problem again, it's in abeyance right now, I'll go the that Throttle Lever Assembly as the fix.
I don't see an OBDII code for that, so it's not surprising it was a bastard to diagnose.
P1128 is related to the Throttle body, either you got a bad throttle control motor or bad throttle body
03-05-12, 10:49 AM
#193
Lead Lap
Thread Starter
Randee973 said his ended up being something mechanical in the TB itself, which is possible because there are bushings and gears between the throttle motor and the actual butterfly valve.
You may want to look at getting an entire used TB and trying that. Greenleaf.com had them when I looked, I think 98-2003 will fit without problem.
It could be the bushings are corroded causing excessive friction on moving the gears or something. There are also a few small orifice holes to allow air flow at idle, if those are plugged or if the butterfly valve is not setting properly then that might also cause the entire system to not feedback correctly causing the limp mode.
You may want to look at getting an entire used TB and trying that. Greenleaf.com had them when I looked, I think 98-2003 will fit without problem.
It could be the bushings are corroded causing excessive friction on moving the gears or something. There are also a few small orifice holes to allow air flow at idle, if those are plugged or if the butterfly valve is not setting properly then that might also cause the entire system to not feedback correctly causing the limp mode.
I'm not too savy with car electronics. So far I've checked the ETCS fuse and it's OK, tested my TB with the TPS, APPS, and ETCS actuator on her car and no change. Also swapped the VSC/ABS ECU and no change. I'm now thinking it's her ECU. How can I test my ECU on her car? Again she has a 98 GS 300 and I have a 2002 GS 300. What parts do I need to swap to see if her car will start with my ECU. Thank you!
03-07-12, 02:20 AM
#194
yeppp hes rightt.. my butterfly was not sitting right for some reason causing my gs to hit the limp mode bs...
i have a back up throttle body if anyone wants to mess with it .. have it as a backup just incase but if the price is right ill sell it... it has no sensors ..
i have a back up throttle body if anyone wants to mess with it .. have it as a backup just incase but if the price is right ill sell it... it has no sensors ..
04-23-12, 04:59 PM
#195
Okay, so I came back to California sooner than I thought.
Update:
I swapped out the throttle body again, no luck.
Two of the o2 sensor was bad. Replaced it.
Swapped out the ecu (the ecu next to radiator) it won't start because it would have to be reprogrammed.
Drove it to a mechanic. He said I'll need a new throttle position sensor (which it was throwing up a code for), and a new fly by wire. So I'm going to try it. He recommended me to go to the dealer.
I didn't check the vsc ecu because it looks like a pain to get to. It looks like it's under the the driver side dash in the diagram.
Update:
I swapped out the throttle body again, no luck.
Two of the o2 sensor was bad. Replaced it.
Swapped out the ecu (the ecu next to radiator) it won't start because it would have to be reprogrammed.
Drove it to a mechanic. He said I'll need a new throttle position sensor (which it was throwing up a code for), and a new fly by wire. So I'm going to try it. He recommended me to go to the dealer.
I didn't check the vsc ecu because it looks like a pain to get to. It looks like it's under the the driver side dash in the diagram.
Last edited by Tuanville; 04-30-12 at 12:48 PM.