Sc 400 Trac Problem

[rexx]

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

[kayka]

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

maybe it could be your gas?

[rexx]

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

maybe it could be your gas?

Gas?

Would that make it go into a 7-8 day cycle? I will admit, I put 89 and sometimes 87 into the tank when it should otherwise be hi-test... Or, do you think it is water related for the gas? I really hate to replace the ECM (or, whatever it is called for the Lexus)...but was hoping for a "oh, that happened to me" kind of response. Thanks for you input....I'm surprised you are the only response at this point on a message board like this. Couldn't hurt to try 93 octane for a month and see if that changes things....I'm desperate for answers at this point just short of bringing it to the dealer for a diagnosis. Had a similar problem with a Jeep Cherokee and it turned out to be a sticking idle control vavle.

[jzz30]

why dont you try and pull the trac. fuse so its not in use for a while to see if its that that is causing the problem.

[rexx]

Where is the trac fuse located, I'll try it? This is different than turning the trac off with the switch? Turning trac off via the switch had no effect but I'll try the fuse. B)

[jzz30]

oh if your trac off botton didnt do anything than its probably not the traction controll. but give it a try anyway.

[teelias]

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

Did you ever figure out what it was. Have similar problem but doesn't go away. Bucks violently when accelerating hard, but not to the floor.

[Air Force Rascal]

New to the forum...

My SC 400 has a wierd hesitation problem. Roughly every 7 or 8 days, the car goes through a wicked surging, stall, spuddering problem. When this happens, the trac idiot light comes on. After about 20 miles of driving when this car is bucking and being a major PITA, it settles out and resumes normal operation for the next several days. During the problem, turn the trac system off seems to do nothing.

What in the world could cause such a cyclic problem? It seems to be independent of environment changes (humidity/temperature). The trac comes on....maybe a throttle position sensor for the trac system? I can't find any minor/major vacuum leaks....just wondering if it is electrical and what is suspect.

I love this car, but would love it more if I could figure this out. Anyone else have this issue?

Thanks!!!

Tom

Could be your fuel pump going out...they can be intermitten at times..before they quit...good luck

[Orlousy]

Same thing for me, it tends to happen every now and then and only when that car hasn't fully warmed up. I keep thinking it's a transmission problem, but I had that checked it the tranny passed with flying colors. If anyone has had this problem and did something that fixed it, please let us know.