Calling all Lexus techs, I need your help!
Calling all Lexus techs, I need your help!
Had a go at cleaning my throttle body, could hear a buzzing noise coming from one of the servos/motors so I unplugged it to check the connection, all was fine.
Put everything back together, now I have an engine management light and the TRC OFF light is flashing at me about once every 2-3 seconds, WTF have I done?
Now for the secondary issue...is my throttle body fu...broken?
I have a series of pictures and a video to show what I think the problems are.
The first thing I notice was that the plate/valve (the gold coloured flap in the TB) doesn't seem to close all the way, it stops about 2mm short of being fully closed, is it supposed to be like this? (picture below)
Note the gap at the top edge of the flap
![[Image: DSC00619.jpg]](http://i462.photobucket.com/albums/qq341/dh-all-the-way/DSC00619.jpg)
I realised that the reason it doesn't close fully is because this grub screw is hitting the stopper and preventing it from fully closing, I left it as it is for now untill I found out if it should be closed fully.
Offending grub screw in centre of picture
![[Image: DSC00620.jpg]](http://i462.photobucket.com/albums/qq341/dh-all-the-way/DSC00620.jpg)
My next issue is the buzzing noise one of the servos/motors is making, this is the offending item...
It's the black box attached to the left side of the TB
![[Image: DSC00615.jpg]](http://i462.photobucket.com/albums/qq341/dh-all-the-way/DSC00615.jpg)
And here's a closeup of it
![[Image: DSC00617.jpg]](http://i462.photobucket.com/albums/qq341/dh-all-the-way/DSC00617.jpg)
As soon as the ignition is turned on and the relays activate, this little ******* thing sits there making a horrible electrical noise like its under resistance all the time.
By twiddling the various sections of the fly-by-wire and fly-by-cable systems I realised that the section that the throttle cable pulls on moves freely and has no resistance.
I can also turn the motorised section of the TB with no resistance.
However when the ignition is on, the electrical side of the TB just doesnt seem to be able to keep up with the movements of the cable side.
Here's a video to show the delay in the cable moving and the motors actually doing anything...(and also of the weird noise it's making)
[youtube]hl4YsXjEGY4[/youtube]
Any advice would be much appreciated guys!
sprinter2012
04-09-2018, 08:12 AM #1First a quick explanation of what's happened...
Had a go at cleaning my throttle body, could hear a buzzing noise coming from one of the servos/motors so I unplugged it to check the connection, all was fine.
Put everything back together, now I have an engine management light and the TRC OFF light is flashing at me about once every 2-3 seconds, WTF have I done?
Now for the secondary issue...is my throttle body fu...broken?
I have a series of pictures and a video to show what I think the problems are.
The first thing I notice was that the plate/valve (the gold coloured flap in the TB) doesn't seem to close all the way, it stops about 2mm short of being fully closed, is it supposed to be like this? (picture below)
Note the gap at the top edge of the flap
I realised that the reason it doesn't close fully is because this grub screw is hitting the stopper and preventing it from fully closing, I left it as it is for now untill I found out if it should be closed fully.
Offending grub screw in centre of picture
My next issue is the buzzing noise one of the servos/motors is making, this is the offending item...
It's the black box attached to the left side of the TB
And here's a closeup of it
As soon as the ignition is turned on and the relays activate, this little ******* thing sits there making a horrible electrical noise like its under resistance all the time.
By twiddling the various sections of the fly-by-wire and fly-by-cable systems I realised that the section that the throttle cable pulls on moves freely and has no resistance.
I can also turn the motorised section of the TB with no resistance.
However when the ignition is on, the electrical side of the TB just doesnt seem to be able to keep up with the movements of the cable side.
Here's a video to show the delay in the cable moving and the motors actually doing anything...(and also of the weird noise it's making)
[youtube]hl4YsXjEGY4[/youtube]
Any advice would be much appreciated guys!
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
FirebirdPhil
04-09-2018, 08:17 AM #2Your grub screw is OK, if the plate closed fully the engine will stall, it does need some air!!
"Life's goal is not to arrive safely at the grave in a well preserved body. But, rather to skid in sideways........
totally worn out and broken, shouting 'Holy ****, WHAT A RIDE!'"
2tongues Your grub screw is OK, if the plate closed fully the engine will stall, it does need some air!!
I did think that but I wasn't sure if it was supposed to be closed until the ignition came on and then the servo would open it itself.
That's one thing off the list anyway.
sprinter2012
04-09-2018, 08:21 AM #32tongues Your grub screw is OK, if the plate closed fully the engine will stall, it does need some air!!
I did think that but I wasn't sure if it was supposed to be closed until the ignition came on and then the servo would open it itself.
That's one thing off the list anyway.
It is recommended that the engine ECU is reset after any engine performance modifications have been made to the vehicle, including using a higher octane fuel, to accelerate the learning of any new parameters. Resetting the ECU will also clear any stored error codes, however if you have a fault with your vehicle it is advisable that these codes are retrieved rather than wiped as they may help in diagnosing the problem.
Make sure the ignition is turned off
Remove the engine bay fuse box cover
Remove the 20Amp/25Amp EFI fuse
Remove the 15Amp ETCS fuse
Wait 30 seconds
Re-insert the two fuses
Install the fuse box cover
It is also possible to reset the engine ECU by removing the battery. Please note that this method will also reset any memory settings such as radio presets, trip mileage, clock etc.
IS200: Resetting engine ECU
It is recommended that the engine ECU is reset after any engine performance modifications have been made to the vehicle, including using a higher octane fuel, to accelerate the learning of any new parameters. Resetting the ECU will also clear any stored error codes, however if you have a fault with your vehicle it is advisable that these codes are retrieved rather than wiped as they may help in diagnosing the problem.
Make sure the ignition is turned off
Remove the engine bay fuse box cover
Remove the 20Amp/25Amp EFI fuse
Remove the 15Amp ETCS fuse
Wait 30 seconds
Re-insert the two fuses
Install the fuse box cover
It is also possible to reset the engine ECU by removing the battery. Please note that this method will also reset any memory settings such as radio presets, trip mileage, clock etc.
If it still shows the waning lights, ideally read the codes with an OBDII reader of some kind, and see what it thinks is wrong. The flashing TRC could be any manner of things, I think, I have certainly seen it a couple of times on my cars! But the codes should narrow down the problem. That said, Gord's advice of a running it for a bit and resetting may cure it.
Not sure on the delay in valve movement, never checked it! Someone will know though, I expect.
![[Image: tempsig2.jpg]](http://i121.photobucket.com/albums/o227/84stoney/tempsig2.jpg)
ad: It was a tough call to make, but the Supercharged IS200 is being retired. ad:Just beat me to it on resetting ECU instructions!
If it still shows the waning lights, ideally read the codes with an OBDII reader of some kind, and see what it thinks is wrong. The flashing TRC could be any manner of things, I think, I have certainly seen it a couple of times on my cars! But the codes should narrow down the problem. That said, Gord's advice of a running it for a bit and resetting may cure it.
Not sure on the delay in valve movement, never checked it! Someone will know though, I expect.
ad: It was a tough call to make, but the Supercharged IS200 is being retired. ad:jae 2010 best lexus category show and shine winner
jae 2010 ice outlaw award 2nd place
jae 2011 ice outlaw award 1st place
is300_dino
04-09-2018, 09:05 AM #6the black denso box is the throttle position sensor, have you had it unplugged at all today? unplug it at the plug end and and make sure theres no **** in the plug clean with electrical contact cleaner and dry off plug it back in, and then reset the ecu, pull fuses efi and main fuse, pop fuses back in then turn the ignition to on but engine off till all lights on dash hopefully all go off then start the car, then let us know what happens, are all the other plugs on the throttle looms reconnected properly?
jae 2010 best lexus category show and shine winner
jae 2010 ice outlaw award 2nd place
jae 2011 ice outlaw award 1st place
And luckily it did, so I now have no more warning lights (another problem crossed off the list)
But I'm still stumped by by delay and buzzing from the TB
is300_dino the black denso box is the throttle position sensor, have you had it unplugged at all today? unplug it at the plug end and and make sure theres no **** in the plug clean with electrical contact cleaner and dry off plug it back in, and then reset the ecu, pull fuses efi and main fuse, pop fuses back in then turn the ignition to on but engine off till all lights on dash hopefully all go off then start the car, then let us know what happens, are all the other plugs on the throttle looms reconnected properly?
I did indeed unplug the connector for the one I showed the picture of, and the plug was spotless inside. (I think it was unplugging this that created the warning lights)
And yes everything else is connected properly.
Is the one I pictured definitely the throttle position sensor? As there's another identical looking box on the back of the TB which is connected to one of the cams the cable system pulls.
The one I pictured seems to be only sensing/controlling the movement of the valve? Or do they both sense throttle position?
sprinter2012
04-09-2018, 09:18 AM #7As you said guys, it suddenly occurred to me that resetting the ECU may remove the lights (I've always done it by taking off the negative terminal for a minute or two)
And luckily it did, so I now have no more warning lights (another problem crossed off the list)
But I'm still stumped by by delay and buzzing from the TB
is300_dino the black denso box is the throttle position sensor, have you had it unplugged at all today? unplug it at the plug end and and make sure theres no **** in the plug clean with electrical contact cleaner and dry off plug it back in, and then reset the ecu, pull fuses efi and main fuse, pop fuses back in then turn the ignition to on but engine off till all lights on dash hopefully all go off then start the car, then let us know what happens, are all the other plugs on the throttle looms reconnected properly?
I did indeed unplug the connector for the one I showed the picture of, and the plug was spotless inside. (I think it was unplugging this that created the warning lights)
And yes everything else is connected properly.
Is the one I pictured definitely the throttle position sensor? As there's another identical looking box on the back of the TB which is connected to one of the cams the cable system pulls.
The one I pictured seems to be only sensing/controlling the movement of the valve? Or do they both sense throttle position?
jae 2010 best lexus category show and shine winner
jae 2010 ice outlaw award 2nd place
jae 2011 ice outlaw award 1st place
is300_dino
04-09-2018, 10:15 AM #8the one on the other side should be the cam position sensor
jae 2010 best lexus category show and shine winner
jae 2010 ice outlaw award 2nd place
jae 2011 ice outlaw award 1st place
sprinter2012
04-09-2018, 10:49 AM #9Also, if any Lexus/Toyota employees read this could you possibly find me a price for a new throttle position sensor. Part number: 89452-53010, if it's not ridiculously expensive I might just replace it anyway just incase thats part of the problem.
I'd take the plug off the throttle position sensor and do a resistance check with a multimeter across the outer most pins.
According to the workshop manual you should be getting 1.25-2.35 KiloOhms @ 20degrees C. If you don't get that then the sensor needs replacing.
If the resistance is ok, I'd remove the sensor anyway to take the cover plate off. Once inside I'd check the the gearing mechanism that connects the throttle control motor to the butterfly valve to make sure nothing was damaged or anything causing an obstruction.
These are just a couple of minor checks you can do if these are ok you'd be looking deeper in the throttle body. Also I'd like to add that it's a lot easier to take the cover plate off the throttle body with the TB removed from the car.
Throttle bodies pop up on fleabay every now and again. I managed to get a complete one for a friend of mine for the grand sum of 99p + £7.00 postage. An absolute bargain if you ask me.
Hope this helps.
It's a real shame the bahamut cars workshop manual doesn't seem to be online anymore.
If I got my fault finding head on, here's what I would do.
I'd take the plug off the throttle position sensor and do a resistance check with a multimeter across the outer most pins.
According to the workshop manual you should be getting 1.25-2.35 KiloOhms @ 20degrees C. If you don't get that then the sensor needs replacing.
If the resistance is ok, I'd remove the sensor anyway to take the cover plate off. Once inside I'd check the the gearing mechanism that connects the throttle control motor to the butterfly valve to make sure nothing was damaged or anything causing an obstruction.
These are just a couple of minor checks you can do if these are ok you'd be looking deeper in the throttle body. Also I'd like to add that it's a lot easier to take the cover plate off the throttle body with the TB removed from the car.
Throttle bodies pop up on fleabay every now and again. I managed to get a complete one for a friend of mine for the grand sum of 99p + £7.00 postage. An absolute bargain if you ask me.
Hope this helps.
It's a real shame the bahamut cars workshop manual doesn't seem to be online anymore.
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