rman310

I have a 1999 LS400 that recently went into limp mode and the error code of P1101 popped up when I read the codes. That is the only code that came up and I spent several hours researching this forum and the web for answers. Eventually decided the Accelerator Position Sensor (part #2206050011) was the problem based on what I read and the error code. I replaced that today and there was no change. Check Eng light and the VSC Off light still comes on. Still have no control over the accelerator unless I put my foot to the floor (in other words, it is still in limp mode).

Any other advise? Should I reset the ECU? If so, do I do that by simply disconnecting the battery for a period of time?

Thanks in advance for any assistance.

- Ross

Kansas

Hmmm, the only terms remember being used for the two sensors in this system are: TPS (Throttle position sensor) and PPS (Pedal Position Sensor) -- which did you replace?

When my 2000 LS400 did the same thing your 99 is doing, the repair shop I use found that TPS was defective and that the PPS was marginal. The replaced both after testing them following the procedure in the repair manuals.

Edit: Please don't take what I said as being a definitive solution to your problem. There are other components in the throttle system besides these two sensors that can fail and cause the problem you are having.

rman310

I replaced the Pedal Position Sensor. Do you know if your car was giving any other codes when they replaced the TPS and PPS?

Kansas

I never asked about the codes. I've been using the same indie Lexus repair shop since 1996 and trust them to do the right thing. I probably wouldn't own a Lexus if that shop didn't exist.

I do know that they tested both the PPS and TPS per the procedure in the repair manual - I think it involves checking resistance or voltage on connector pins. I may have posted the procedure on this forum but I don't remember. I have only a hard copy of the repair manuals and they are thick and difficult to scan. A diagnostic procedure for something seemingly simple can take up 20 to 30 pages in the repair manuals.

My gas pedal was the same as yours -- mainly unresponsive with the gas pedal going to the floor with little effect. Turning the engine off for a few minutes got the gas pedal working enough to get the car home and I limped it to the repair shop the next day.

I've rebuilt engines but these cars have become too complex for me to (want to) do more than basic maintenance. I've found it cheaper to have my former Lexus dealer mechanic "Fred" figure this stuff out.

Kansas

I found an electronic copy of how how to test the TPS, PPS, etc. Hope it helps.

mgillespie

I had this on my 99 .a loose battery connection seemed to be the problem .happened three times in one day that was two weeks ago .