Check Engine Light

[ducatist4]

I searched for a similar problem but couldn't find one. I have a 92 ls400. The check engine light came on while I was driving on the hiway, about 75 mph. I pulled over and checked all fluids, they are O.K. Started the car and the light was off. Continued on, back to hiway speed, and the light came on again. The car was running fine. I noticed that when I passed someone that it would not down shift. I slowed down and pressed full throttel with no shift result. Pulled over again, put car in park, shut off, re-started, Check engine light went off, car shifted fine. As long as the check engine light was off it shifted fine. When the CEL was on I was able to shift with the O/D button. I think that when I was using the cruse controll it would shift fine also. Can't be sure though, no hills steep enough to check.

No lexus dealers or auto zone to use diagnostic computer. I am going to a independent to see if he can check.

So if anyone has had a similar problem, A responce would be appreciated. Also where can I get my own diagnostic computer??? What is the best brand to buy??

THanks in advance..

This web sight is great.

[LScott400]

LexLS.com has the following tutorial:

How to Read & Clear Diagnostic Trouble Codes

[ducatist4]

Thanks LScott

I was able to take it to a indy. He has a computer, hooked it up and it was a code "41". TPS Will order one and have it replaced.

I would still like to know what diagnostic computer is avaliable. I would like to purchase one specific to this car.

Thanks again

[LScott400]

My '94 had a code 41 and a TPS did not fix the problem. Hopefully, that won't be the case with yours. Ended up exchanging the ECM.

As for the tester specific to these cars, This is an old promotion for the factory tester. Don't know if your up for this kind of expense. Maybe someone else on here can tell if you if there is an aftermarket that will work your vehicle's OBDI interface and what the limitations would be as compared to the factory unit.

[92Lex]

Did you figure out what the problem was?

[ducatist4]

Not yet 92 lex

Haven't got the tps yet. I have contunied to drive the car and of course the cel won't come on. After lifting the hood and wiggeling the wires on the tps seems to have fixed the problem. I am going to change the tps anyway.

LScott, was there anything that pointed to the ECM? You said that you changed the ecm. Did you have yours rebuilt or purchase a new one??

[LScott400]

The details are in this Post.

[LScott400]

The code 41 was eliminated when I replaced the capacitors in the ECM. Post.