Lexs400

93 LS400 w/trac.
I had the Trac Light on which reflected a bad TPS sensor (as per the dealer), so I had that replaced and the Trac light went away.
yesterday, I figured i should remove the other TPS look alike sensor on the left of the TPS to clean that up. And when I put that back on, the Trac light came on again. Keep in mind that this time the TPS sensor was not touched at all.
Anyhow, I took the negative terminal of the battery off for overnight, but this morning the TRAC warning light is still there.
any ideas/help on how to resolve this. ?
I know there is a section on adjusting the TPS but what about this sensor to the left of TPS. how is this one adjusted ? and how can i clear the codes, if disconnecting the battery isn't doing the trick ?
thnx everyone. please reply back as it's snowing in NJ and i need the traction !

VVT-i

Look like the sensor on the left( if you opened the hood and looking at the engine) is the Trac sensor before the TPS. Can you loose the screws and move the sensor, so the screws are sit in the middle of the slot on the sensor.

Then, remove the EFI fuse for about 1 minute. Good luck.

FYI, those sensors don't need to be clean. You may damage the sensor when you're try to clean it.

Lexs400

thanks for the reply.
i did extensive research yesterday on this site and came up with the conclusion that removing the EFI fuse for a minute is the "best" method to clear the trac light.
too bad i read the response to the email after i struggled all day yesterday trying to jump the OBD switch pins under the dash/hood without any luck.

The best way was the removal of the EFI fuse, it's on the right side of the hood right behind the battery. there is a black box cover, two screws hold it on top of the fuse box.
the fuse for EFI is a 20A fuse. however here is a cylinder shaped fuse/part that says EFI as well. not sure what that was but i removed that as well to be on the safe side.
now the trac light is gone !

The dealer quoted me $395 to change the TPS. 110 for the part and two hours labor ! how can taking two screws out and replacing the TPS equate to two hours of labor ???
anyhow, the moral of the story is to use the "search button" on this site.

Dx3

iTrader: (13)

this should be written on the very first page of CL in very large red letters!!



Glad you got your problem fixed,
Jonny

Lexs400

agreed most of the times I find that info faster using search because not everyone might frequent the site daily and if so have the time to reply to everyone's posts especially if they have done so in the past.

I also have a comment regarding disconnecting the battery to remove the codes.
I had the battery removed numerous times, for longer than 2 hours in order to remove the code but that didn't help.
Removing the EFI fuse did the trick.
Some posts suggest that removing the battery does work. I am curious to find out when one method works over the other.

Lexs400

I guess I spoke too soon !
starting the car again just a while ago came back with the "trac" light again.
at this point, i'm curious to know how to adjust the sensor for traction which is adjacent to the throttle position sensor (TPS).
I have searched and read how to adjust TPS manually, but there are no threads on how to adjust the similiar sensor for traction.
anyone care to comment ?

Lexs400

while searching for TPS i noticed that the TPS for 92ls w/trac was different for the 93ls w/trac
given they're different number, would they still be interchangeable ?
if not, what's the reason ?

tyncobb

I am having the same problem with my trac light on my 94LS400 @ 155K miles. It is being repaired at the dealer as we speak. Told them I thought it was the TPS or oxy sensor and they ran a code, that said the problem was not the TPS/oxy sensor; but the hose and "o" ring that connects to the accuator pump (part of the ABS). Apparently it is crimped or has a leak and is not providing enough pressure into the accuator, therefore, the Trac Light goes on when the pressure is down. The light has been coming on during normal driving conditions for several hours, then it might not come on the next time I start it. Seemed to begin when the weather dropped down to 32 or lower. However, it does not always come on, so it is not related to the temperature. The repair price is $95 for hose, $12 for the O ring and 2 hours labor. Hope that fixes it. If not, I am told it could be the accuator pump and that would run about $1000. I'll keep you posted on the results.

Lexs400

allright,
the trac light was fixed by the tps and sub tps adjustment. now to the real deal.
the car has hesitation during acceleration, and even after all the fine refinements of tps, the hesitance is there. i turned the O/D off, and noticed a less smooth acceleration at speeds where usually the o/d gear would pick up.
the acceleration is perfectly fine when the car engine isn't fully warmed up.
curious to knw what might be causing this..