Check Engine Light, Car Limps, VSC Lights on...Please Help.
#46
Lexus Test Driver
iTrader: (22)
My car did this same thing the other night. I was sitting in line at the car wash and went from park to drive and my VSC light went on. My CEL went on and then all three of those lights lit up. I drove it home, put it in the garage for a while. Came back out and started it and they were still on. Backed the car out of the driveway and all 3 of the lights went off. Haven't had anything since then.
PLEASE keep the thread updated as you diagnosis.
PLEASE keep the thread updated as you diagnosis.
#48
"Drive By Wire"
Not to be rude, but the term "Drive By Wire" can mean several things.
The most comon meaning is that Electrical signals are used to move / adjust systems, rather than linkage etc....In the case of the 2nd Gen GS300/400 its 99% drive by wire, and 1% old fashioned way:
In 2nd Gen GS300/400 The Throttle Cable DOES NOT do the work in opening the Butterfly Valve inside the Throttle Body.
The Throttle cable is simply an extension of the accel pedal movement to an electrical sensor monted on the throttle body. That sensor via an electrical WIRE sends signals to the ECU which then sends signals to the electrical throtle motor located near the front left side of the throttle body which actually opens the butterfly valve.
The Accel Pedal sensor which is located on the back side of the throttle body, which senses how far the pedal is depressed via the cable could be mounted inside the cabin, and the cable eliminated....however:
As a safeguard to allow people to get home in the event of an electrical malfunction, lexus decided to keep the throttle cable from the pedal to the throttle body and allow the last 10%+/- of cable movement to engage the butterfly valve.
I 100% guarantee you this is the case, I have an extra throttle body taken apart, and without power moving the throttle cable does NOT move the butterfly valve until the last 10% or so.
"Drive By Wire", in the 2nd Gen GS300/400, is therefore a Hybrid-style system in which it utilized old and new technology. However for 99.99% of the driving, its done using only the electrical signals from the cable moving a sensor, not from the cable itself.
Now...on to explaining nuclear physics
Last edited by az-dave; 10-23-09 at 05:19 PM.
#49
Guest
Posts: n/a
I have never had this issue. Cleaned the MAF and Throttle Body today. Damn VSC and VSC off button pops up. The radio and clock don't come on (I did reset with the 20 ECU).
The odd thing is the car is very responsive now, much better than before. It is not in limp mode. So I'm confused.
I had the check engine light on before and I know the issue, its the cats. I have already replaced my 02 sensor, the long one as it failed last year.
I swear I see why people just get new cars
The odd thing is the car is very responsive now, much better than before. It is not in limp mode. So I'm confused.
I had the check engine light on before and I know the issue, its the cats. I have already replaced my 02 sensor, the long one as it failed last year.
I swear I see why people just get new cars
#50
Driver School Candidate
Join Date: Aug 2008
Location: ALABAMA
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Check Engine Light, Car Limps, VSC Lights on...Please Help.
Ok..well Im going to Post this in this Thread, and start a new thread also.
I replaced the Idle valve Motor, which is the larger electrical object next to the TPS on my 98 GS300. Problem is solved.
The Codes I got were P1120 and P1121 - Accelerator Sensor problem. However it wasnt really the Accelerator Sensor, it was indeed to actual electrical Motor that controls the opening of the Butterfly valve inside the Throttle body.
My symptons were:
VSC, VSC OFF, and ENGINE Lights would come on, followed shortly by my car going into Limp Mode, where only that last 25% (if that) of the throttle would respond (basically have to floor the pedal to even move at all).
The first part I tried was the Throttle Position sensor, which is on the front side of the throttle body, and the easiest thing to replace...this didnt help at all.
Next, with some trouble shooting, and using an ohm meter to see if the throttle electric motor was getting elev, I found that the elec motor just to the left of the TPS was basically freaking out and shutting down. The Accelerator Pedal Sensor is on the Back-side of the throttle body where the throttle cable connects to, and has a spring on it. It was fine.
GS300's are indeed "drive by wire" concerning the throttle...the cable triggers the Accel Pedal Sensor, which sends a signal to the ECU, the ECU then sends power to the Idel Valve Elec Motor (next to the TPS), which opens and closes the mechanical butterfly valve, then the TPS sensor detects how far the elec motor is actually opening the butterfly valve...its a closed-loop feed-back system, meaning any failure in any sensor will cause the entire systm to fail.
The throttle cable apparently is ONLY there to allow the fail-safe of having that last 10-25% throttle when the electronic system fails...there is a gearbox inside the throtle body which allows the tail end of the throttle to manually engage the butterfly valve...the rest of the time, the butterfly valve is 100% opened and closed via the idle control motor.
I replaced the Idle valve Motor, which is the larger electrical object next to the TPS on my 98 GS300. Problem is solved.
The Codes I got were P1120 and P1121 - Accelerator Sensor problem. However it wasnt really the Accelerator Sensor, it was indeed to actual electrical Motor that controls the opening of the Butterfly valve inside the Throttle body.
My symptons were:
VSC, VSC OFF, and ENGINE Lights would come on, followed shortly by my car going into Limp Mode, where only that last 25% (if that) of the throttle would respond (basically have to floor the pedal to even move at all).
The first part I tried was the Throttle Position sensor, which is on the front side of the throttle body, and the easiest thing to replace...this didnt help at all.
Next, with some trouble shooting, and using an ohm meter to see if the throttle electric motor was getting elev, I found that the elec motor just to the left of the TPS was basically freaking out and shutting down. The Accelerator Pedal Sensor is on the Back-side of the throttle body where the throttle cable connects to, and has a spring on it. It was fine.
GS300's are indeed "drive by wire" concerning the throttle...the cable triggers the Accel Pedal Sensor, which sends a signal to the ECU, the ECU then sends power to the Idel Valve Elec Motor (next to the TPS), which opens and closes the mechanical butterfly valve, then the TPS sensor detects how far the elec motor is actually opening the butterfly valve...its a closed-loop feed-back system, meaning any failure in any sensor will cause the entire systm to fail.
The throttle cable apparently is ONLY there to allow the fail-safe of having that last 10-25% throttle when the electronic system fails...there is a gearbox inside the throtle body which allows the tail end of the throttle to manually engage the butterfly valve...the rest of the time, the butterfly valve is 100% opened and closed via the idle control motor.
#54
Please post a link to the claimed free fix...
I think you are mistaking Lexus and Toyota replacing Acel Pedal sensors (the ones on newer 3rd gen+) where the sensor is located at the pedal itself (cars with no throttle cable).
These older TB's utilize a completely different system, are old, and there is no C.A. or free fix that Ive ever been made aware of...especially for 17+yr old cars ;-)
I think you are mistaking Lexus and Toyota replacing Acel Pedal sensors (the ones on newer 3rd gen+) where the sensor is located at the pedal itself (cars with no throttle cable).
These older TB's utilize a completely different system, are old, and there is no C.A. or free fix that Ive ever been made aware of...especially for 17+yr old cars ;-)
#55
It is your thread Holmes:
https://www.clublexus.com/forums/per...p-mode-37.html
Check post 544 out. There is one post that has a PDF with good info on it. Revisit your thread
https://www.clublexus.com/forums/per...p-mode-37.html
Check post 544 out. There is one post that has a PDF with good info on it. Revisit your thread
Thread
Thread Starter
Forum
Replies
Last Post
SeanIS350
IS - 2nd Gen (2006-2013)
17
09-18-15 08:31 AM
jhp9mm
LS - 1st and 2nd Gen (1990-2000)
27
02-28-14 01:27 PM
jennbrad
ES - 1st to 4th Gen (1990-2006)
4
06-11-08 02:02 PM