Intermittent Warning Lights

[rtd111]

91 LS, 152K miles.

About early 2006, my Lights (indication for headlight/tailight/halogens/etc issue) warning light came on. I checked the lights and noticed one of the halogens was not working so I attributed it to that. However, one day I noticed that it was working but the warning light remained on. I ignored it.

About the same time as the Lights, my TRAC light had also come ON. The TRAC light was intermittent: sometimes it would come on when starting, sometimes after I drove a few (tens) of miles, and sometimes, though rarely, never came on during a drive.

About 2 months ago, the check engine light (CEL) popped up as well as the Traction Control ON/OFF light. These would come on within a mile of driving. So at first opportunity, I ran some diag and got code 41 (this was the only code), which indicates a Throttle Position Sensor issue. I removed the TPS, cleaned the leads and put the same one back in. Cleared the codes. These CEL and Traction OFF lights went away. I ordered a new TPS in the meantime, which till today remains in the box.

When I cleared the codes after the TPS cleanup, all warning lights were gone. However, afer a couple of days, the Lights and TRAC warning lights came on as previously described. This continued for about a month. About a week ago, these disappeared. So now, I have no warning lights.

This is a little bothersome. Any ideas? Any suggestions for further diag?

[backyard_famer]

ES300 125k

I had a couple of lights come on tonight. Where did you run the diagnostic codes?

Thanks,

backyard_farmer

[rtd111]

ES300 125k

I had a couple of lights come on tonight. Where did you run the diagnostic codes?

Thanks,

backyard_farmer

You did not mention year of your vehicle.

For me, the OBD codes are in the FSM, or check http://www.troublecodes.net/Lexus/

BTW, the TRAC light came on towards the end of a (~15 mi) trip. On the way back, nothing. I should have mentioned that I changed the wires, plugs, dist and rotor earlier in the year after which the TRAC warning light started appearing as described.

[mann777]

Sometimes when the battery is slowly dyng you do come across such symptoms, when did u last change the battery. Just curious , I had these problem way back, all was the battery replacement and all dissappeared.

[Paul Sherman]

RTD1111 said:

'I ran some diag and got code 41 (this was the only code), which indicates a Throttle Position Sensor issue. I removed the TPS, cleaned the leads and put the same one back in. Cleared the codes'

I have a Code 45 with the 'TRAC' light. When I posted someone suggested cleaning

the TPS. Is your action what they may have suggested? Pull the TPS's (have two, due

to traction control) and clean the leads where the harness plugs in?

[rtd111]

RTD1111 said:

'I ran some diag and got code 41 (this was the only code), which indicates a Throttle Position Sensor issue. I removed the TPS, cleaned the leads and put the same one back in. Cleared the codes'

I have a Code 45 with the 'TRAC' light. When I posted someone suggested cleaning

the TPS. Is your action what they may have suggested? Pull the TPS's (have two, due

to traction control) and clean the leads where the harness plugs in?

Sorry for the delay; I've been away.

I do not know anything about code 45 or about the suggestions to fix it. I did not have a new TPS so I did what I could by way of investigation/isolation. I was not expecting the code to go away -- though its hard to tell if its really gone. I have not driven the car since my last posting. And I just took a lint-free cloth and rubbed the leads carefully for a few seconds to clean off any deposits (or my fingerprints :-) -- kinda std procedure. I am not even sure what cleaning means: perhaps some solvent to really dissolve anything that might be on it but I don't know.

Can't be of much help to you.