OK LS fan boys & girls, I've got a strange conundrum that just surfaced this weekend, so hoping someone might have some insight into this slightly irritating problem. I just replaced the coolant temperature sensor on my '98 LS400. It was pretty straightforward, no big surprises.

The surprise came afterward, however. Upon getting everything buttoned up, I go to start up my car. No strange noises or anything, but within about 15 seconds of starting the car my VSC light came on. Make that, my VSC off light came on to be exact.

Pray tell, what happened in the span of me simply replacing my coolant temp. sensor? I didn't really do that much as far as removing wires. Has anyone had the same experience on their 98-00 LS? Would be interested to hear your input and stories in this regard.

 

Did you disconnect the battery cable before the replacement job?
If so, the ECU needs to do the presetting spending nearly 20 seconds. Next time when you start the engine, don't turn the key fully and wait about 20 seconds+ at ON position and then run the starter motor.

 

Yamae - to your question, I did not disconnect the battery cable before replacing the coolant temperature sensor. I've been driving the car for a couple days like this with no ills effects, other than the VSC off light.

In light of this, would you recommend going back and disconnecting the battery cable? Your thoughts please . . .

 

Try disconnecting the battery cable. Only negative side is enough. Wait 10 minutes and connect again.

Turn the key clockwise but don't start the engine. Wait at the position "ON" or "RUN" until the VSC light turns off and start the engine. Depending on shipping destinations, Toyota used "ON" or "RUN".

Run the car right after that and see the VSC light turns on or not.

 

Rule number one on these cars if your going to do anything to the electrical system, other than tail lights, head lights and other such easy type lights always disconnect the battery. I suppose pulling a fuse would be acceptable as well.

 

Yamae & Dicer: copy on the directions both of you so kindly gave me as input. I will go ahead and disconnect the battery cable (negative) for at least 10 min. and proceed as you described. Will let you know the outcome . . .

 

Just wanted to give you guys an update. Disconnected the battery cable (negative) this afternoon. Waited 15 min. and tightened it all back up, drove the car and all is fine. No VSC off light is coming on now, so thanks for saving me the hassle.

 

Yeah disconnecting the battery usually solves the VSC light as long as there is nothing else going on with the car.