coolchicky

1990 LS400: My fuse for the horn/emergency lights keep blowing. It works momentarily but seems to blow when the ignition is turned off. Could this be related to the theft deterrent system (module)? Anyone remember if there was a recall bulletin for this problem. Many thanks!

Update: My mechanic pulled a diagnostic trouble code of P0446 which relates to a service bulletin regarding a "false M.I.L. 'ON' DTC P0446 on some 1999 year ES 300's". The bulletin covers a certain VIN range which mine happened to fall under. This calls for the addition of Vacuum Control Valve (PN 25852-20010) which requires .5 hours. My dealer ended up charging me for 1.0 hours. They said the job was a bit more complicated than originally quoted. After waiting an hour already I gave them the go ahead (incompetent mechanic I suppose). Anyway, the part cost $34.09. I'll keep the forum posted if problems persist. This is from a post of mine on Oct. 20, 2006. I've driven over 1700 miles since the fix and no problems

This is from my post on Oct. 20, 2006 regarding a similar issue: Update: My mechanic pulled a diagnostic trouble code of P0446 which relates to a service bulletin regarding a "false M.I.L. 'ON' DTC P0446 on some 1999 year ES 300's". The bulletin covers a certain VIN range which mine happened to fall under. This calls for the addition of Vacuum Control Valve (PN 25852-20010) which requires .5 hours. My dealer ended up charging me for 1.0 hours. They said the job was a bit more complicate than originally quoted. After waiting an hour already I gave them the go ahead (incompetent mechanic I suppose). Anyway, the part cost $34.09. I'll keep the forum posted if problems persist. There is another recent thread regarding this problem...do a search, it might help.

The Toyota dealer charged $90/hr. I was satisfied with their work. Time will tell if this was the correct fix.

Update: My mechanic pulled a diagnostic trouble code of P0446 which relates to a service bulletin regarding a "false M.I.L. 'ON' DTC P0446 on some 1999 year ES 300's". The bulletin covers a certain VIN range which mine happened to fall under. This calls for the addition of Vacuum Control Valve (PN 25852-20010) which requires .5 hours. My dealer ended up charging me for 1.0 hours. They said the job was a bit more complicate than originally quoted. After waiting an hour already I gave them the go ahead (incompetent mechanic I suppose). Anyway, the part cost $34.09. I'll keep the forum posted if problems persist. Thank you for all of your advise.

Is this something I can do or do I have to take it to a Toyota/Lexus dealer?

Never mind...I just read the post below and now at least I have a direction to look.

I have a '99 ES 300 with about 85K mi. Recently, the Trac light and Check Engine light came on simultaneously while I was doing about 65mph. Just cruising. I took it to my mechanic and his computer gave him an indication of emissions. He said that 90% of the time it's caused by venting or loose gas cap. He reset my computer, both lights went off and I installed a new cap...made sure it clicked when tightening. All was well for about 300 miles or so but now both lights are on again. Any ideas or recommendations? I don't want to go to the Lexus dealer. Thanks!