Odd Problem With Lights

[saint_ex]

Hello all,

I've encountered an odd problem with my 99 ES300 (approx. 210,000 miles). I suspect it may be the problem with the wires, but I would like your input.

Whenever I turn the lights on, on my dashboard, R lights up and the rear-light-not-working warning indicator light goes on. At first, I thought that one of the reverse lights was out. But they were both working fine (that one time I checked).

So, when those lights on the dash are on, and I go to put it in Reverse to back out of the driveway, it feels as though it violently jams the gear into reverse (note, just before that, P and R on the gear indicator are both on). Once I back out of the driveway, I put it in drive, and I have no problem taking it out of R. At that time both R and D are on and will continue to do so. If I, however, turn the headlights off, the R will disappear, but I cannot, obviously, drive it without the headlights.

If I shut the car off, and turn it back on for the second time, I get CEL with a transmission code (sorry, I cannot remember the specific code, it was checked about three weeks ago, but I know that I had looked it up and it was a generic transmission code). Anyways, CEL goes on. During the day, when the headlights are not on, the CEL will stay on for the first couple of times (usually 3) of car being turned on and off. I guess that it does its self-check, it doesn't find the fault after several miles of driving or several ignition starts, or whatever it does, but it turns itself off. And, then, at night, the same story will repeat. I think that it gets confused with 2 lights being on at the same time and that is why it kicks out the CEL.

Today, I have checked the reverse lights at the back of the car, and they are both off. I had a quick look in not-so-great lighting conditions, but they seem fine.

Here is the final problem. The trunk won't open either via remote or by pushing the button in the car. So, I really have a feeling that there may be something wrong in the wire. If that is the problem, what is the best way to figure out where the problem is (I hope nobody will say that I have to rip the carpets off to get to the underbody and all the wires that are there)?

Or, does anybody have an idea of what this could be, and how to get it fixed. Thank you for the help.

[CUMan]

This sounds very similar to a problem very common with the early 90's LS models. I have never noted this being discussed as a problem with the ES models; however, It could be possible.

The problem with the LS models involves a wiring harness which is attached to the driver side trunk hinge. There is not enough slack in some of the wires in this harness, and the opening and closing of the trunk apparently stretches some of the wires to a point where they break. When that happens, all kinds of electrical problems become evident. Illumination of the "R" in the transmission gear indicator is a common occurrence. Transmission shift patterns are often affected, and brake applications can feel strange. An inoperative trunk release is also very common.

In the LS models, the most common wire that is affected is a white wire with a black stripe. As I recall, this is a ground wire. With so many different things being affected in your car, I would suspect that a defective ground is also involved here.

I would start with the inoperative trunk release. Using a multi-meter, try to determine if the switch is getting power and if the ground to the switch is okay. If the ground has failed, you may have found the source of your problem.

[saint_ex]

Thanks for the reply. I think that you're onto something. I did do a search on LS400 forums and I did find some treads with exact same symptoms. I will be looking into it sometime in the near future.

Again, thanks for the help.