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Yes, on the presumption that your headlights stay constantly on when you switch them to "on" at night then you have a failing or failed solar radiation sensor/system. You might try covering it help to see if that helps.

Are tire chains legal? I didn't think they were everywhere. You may be thinking of studded tires. I don't know of any state wherein tire chains aren't legal provided their use is warranted.

Yes. For the utmost in ride comfort and quietness I have Bridgestone Turanza summer only tires. Run them all rear around and use tire chains if/when the need arises.

No, early, premature failures are resulting from excessive frictional surface wear of/on internal clutch surfaces as a result of "safer" FWD shift pattern/schedule adopted by Toyota(Lexus) late in the last century. If the transaxle needs to downshift due to a requirement to accelerate following, QUICKLY following, a FULL lift throttle event (putting the engine at idle) resulting in an upshift being commanded by the ECU, then the ATF pressure will be exhausted when the subsequent downshift finally begins. Due to the SOLID coupling twix the gas pedal and the throttle butterfly valve the engine RPM will begin rising the instant you start depressing the gas pedal. Meantime that previously commanded upshift must complete which will mostly exhaust the fluid pressure needed to quickly seat the clutches for the upcoming downshift sequence. Like slipping the clutch, SEVERELY so, on a stick shift each and every time you downshift. On an automatic that required "slipping the clutch" effect is one of the purposes, functions, of the torque converter, NOT actual clutch slippage. DBW was adopted to alleviate these premature transaxle failures by delaying the onset of engine torque. Which might also go to explaining a seeming anomally in my 2001 AWD RX300. My RX has a VC, Viscous Clutch/coupling mounted across the two output shafts of the otherwise open center diff'l. The VC will not "lock" the center diff'l absent a persistent level of disparate rotational rate for two, front vs rear, diff'l drive outputs. But my Rx has VSC/TC/etc, etc. The instant either front wheels begins to slip/spin TC will start braking both front wheels "moderately", and at the same time "dethrottle" the engine via EFI implemented fuel starvation. So of what use does that make the VC? None? Apparently so, since for the RX330 and entire rest of the FWD based AWD vehicles the VC was dropped. WHY...? Using the VC as was intended would clearly put additional stress on the drive train. Absent TC, my RX300 would operate on aderse, slippery, roadbed surfaces as the original design engineers intended. But by the time the '01 was being put into product Toyota(Lexus) knew that the '99 RX300 transaxles wer failing prematurely for the above stated reasons. How to take the additional stress of a "true", VC implemente, AWD system, off of the drive train, how too "protect the drive train"? QUICK, install some new code, firmware, and have the TC system prevent the VC from actually putting the system into AWD "mode". Firmware revision vs hardware...ALWAYS. But in this case.... You get both.

The initial, FIRST, TSB that I'm aware of that addresses the 1-2 second transaxle downshift delay was issued by Toyota in the spring of 2003 for the 2003MY Camry. I understand that the 2003 was the first year the DBW system was used on the Camry "to protect the drive train". So, like my 2001 AWD RX300, built before DBW, the 2002 Camry may be inordianately subject to premature transaxle failure due to the new "safer" FWD shift pattern/schedule adopted late in the last century. Personally I will NEVER buy a FWD vehicle and NEVER rent one during the winter months in my travels. But then maybe I value my life moreso than others on this planet.

Does your '02 Camry have BA, Brake Assist, as likely does your (earlier MY{??}) Lexus? Unless you "trigger" the BA system the brake pedal will typically have "more" resistance.

But what about your dear "other's" driver's ed teacher?

Left foot just "resting" on the brake pedal, maybe?

If the compressor is kicking on and off then the expansion valve is NOT likely to be your problem. But the remix/reheat airflow path servomotor is. The expansion valve is used both to separate and to "meter" the flow of liquid refrigerant from the compressor high pressure side into the evaporator and thus into the low side. In the evaporator it transitions from a liquid to a vapor via wicking the heat from the inside of the evaporator cooling vanes and thereby indirectly cooling the system airflow. Were I you I would go to Home Depot and buy a manual water shutoff valve and install it in the inlet line to the heater core. Shut off all of the HOT water flow is see if you cooling level isn't a LOT more consistent. In the long term you can use that valve along with other measures to improve the overall perfromance and efficiency of your climate control system, and gain a little FE improvement too Turn the hot water flow off during the summer months when all it does is lower the system efficiency in order to not discomfort you with raw A/C functionality. Until Lexus came up with 2 C-best options to accomplish the same I always disconnected the A/C compressor clutch during the winter months.

I hope that was R134a not "freon". In any case there is a rotation rate sensor/detector that is used to be sure that when the clutch is engaged the compressor is rotating at a rate cognizant with the RPM of the engine. Undoubtedly the sensor gap is not quite small enough and only works properly at higher engine RPM. Electromagnetic sensors are like that. Thanks for the reply. It was charged withR134A, my poor choice of words. Is the sensor gap adjustable on the sensor or is that done with compressor clutch shims? "adjustable..."? I have no idea, really. But what I would first do if I really needed to know personally is go out and pop the hood and look over the sensor "arrangement". If I didn't learn anything usefull that way I would then look in my shop/repair manuals. Let me know if you need me to "crack the books".

My guess would be that the reheat/remix blend door/vane servomotor or servomotor position feedback is malfunctioning. If the compressor is running then you're not TOO low on refrigerant. If the expansion valve were blocked or restricted the compressor would run just long enough for the high side pressure to trip the limit and then shut down. In max cooling and high OAT the compressor might well run continuously. Block the hot water flow from the engine to the heater and you will have cooling.

"depends on if its AWD or not.." I'm not so sure all of the votes have been counted on this one yet. The AWD model will undoubtedly put more stress on the transaxle and that would UNDOUBTEDLY result in earlier and a higher number, overall, of premature transaxle failures. The failures seem to occur at about 70-100,000 miles and here we have a '99 model with 82k miles. ~10,000 miles/year, is that high or low for the US fleet? Setting here typing this, 1st coffee in hand, put me to wondering again about these transaxle failure. I traded up from a 2000 AWD RX300 to a 2001 AWD RX300 just as soon as the latter came out. My primary reason was to get HID headlamps as at age 60+ my eyesight was not as good at night as it once was. But the '01 also had VSC/TC/EBD/BA along with ABS. It wasn't long before I began to question the idea of a VC, viscous clutch/coupling based AWD system AND TC (Traction Control), at least TC as implemented on my '01 RX300. In order for the VC to "lockup", partially couple the rear driveline into the front, the disparate rotational rate resulting from slipping of the front wheels vs the rear must exist for at least a few seconds. The two sets of clutches plates rotate in different directions, higher and higher in rate as the difference in F/F traction, wheelspin/slip grows. That results in heating of the VC fluid within the hermetically sealed VC case. The fluid, which is specifically formulating for an exceedingly high expansion rate with temperature rise increases in pressure, thereby raising the coupling coefficient between the two sets of plates effectively "locking: the otherwise fully open center diff'l. The problem with my '01 AWD RX300 is that the instant those front wheels develop even the slightest level of wheelspin/slip the Traction Control system activates and begins to moderately brake, "pulse" modulate the braking at the front. That, of course, as in the MB ML320, would result in maintaining a high level of driveline, engine, torque, and the rear wheels would be forced to pick up some of the "drive" load. Maybe in the ML320, but not in my '01 RX. At the same time TC begins braking the front wheels it also quickly dethrottles the engine. '01 RX300 AWD......NOT! But then I have known that pretty much from the get-go and made compensations accordingly...called a 1994 AWD Ford Aerostar for when the going gets rough. Snow and ice mind you, NOT, NEVER, off-road. But, back to the sbject at hand. Does the TC in my '01 AWD RX300 activate to help me get unstuck or just up and going or since the VC should, would ordinarily, be used for that is the TC "tuned" to protect the drive train? I know that in my '92 LS400 when TC activates the simplest, BEST, thing to do is reah over and turn it off and then do your own throttle feathering to get out of those tough "go" spots. The '92 LSes TC not only pulse brakes the drive, rear, wheels, it also quickly dethrottles the engine. Later Lexus RWD models with TC will still instantly pulse brake the rear will but will delay the onset of dethrottle to get the driver time to react to the conditions and "lift" the throttle and then begin feathering it so as to move forward. I have always wondered, since the TC implementation makes it virtually useless, why my '01 even had a VC. Then the VC was dropped for the entire Toyota and Lexus FWD based AWD fleet with the advent, time of, the RX330 introduction. Apparently it has returned for the RX350 series but as yet, insofar as I can determine, not any of the other products. Has anyone out there enough experience, wintertime experience, in the RX350, to be able to say if the TC activates immediately or is it delayed to allow the VC to be effective, somewhat effective? Since Toyota and Lexus have now acknowledged that DBW was adopted primarily to "protect the drive train". Kkeep the engine "at bay", dethrottled, until a downshift for acceleration, one proceeded by a lift-throttle upshift, could complete. So it isn't so outlandish to propose that TC, as implemented in my '01 and later RX300's, was also done to protect the drive train, prevent the premature trasaxle failure from carrying over to the nest and succeeding MY products.

These days, with most, you simply hold the button down for a few extra seconds after the window reaches the end of travel.

There is an unusual design aspect of the '92 LS400's A/C system that even your (even were it true) "highly regarded" mechanic might be unaware. It has an EPR valve upstream of the evaporator core. These are more commonly used to "meter" the high side liquid refrigerant when two or more separate evaporators are used on one compressor/condensor system. Without the EPR one evaporator could potentially HOG all of the cooling capacity. Front/rear A/C setups in minivans for instance. I have come to believe that Lexus used the EPR to lessen the noise factor "HISS" that you might otherwise get with 200 psi pressure differential between the liquid and gas side, across the input and output of the expansion valve. The Lexus EPR valve, even during "normal" operation can/will often allow refrigerant cooling capacity to exist beyond the evaporator core, and into the refrigerant return lines to the suction side of the evaporator. After a long period of operation on a humid day I often see 1/4 of rime ice accummulated on these return lines. So, should the EPR valve be maladusted (it has a "back-pressure" adjustment) or fail in a way that causes liquid refrigerant to reach the compressor inlet, the compressor life will be shortened substantially, due to something called compressor "slugging".

Agreed, seconded. I'll 3rd that. I think you need to drop the "highly regarded" from his title. Compressors are designed to run on R134a. When a conversion is done it's important to get all of the r12 out of the system since the 2 refrigerants are not compatible. Also important to use the right kind and amount of compressor oil. I also replaced all the o-rings when i did mine. May have been overkill but many recommend it. I suspect that there was something missed on your original conversion to R134. Check out Tech Choice Parts, or AC Parts Now. I bought AC parts from both places and was happy with prices and service. Then find another reputable mechanic. "..the 2 refrigerants are not compatible." In what way. I know that this is common knowledge, commonly accepted knowledge, but I have never seen any evidence or proof of same. My A/C specialist says that the only reason to pump down the system of R12 is to remove the potential for any residual R12/22, freon, from simply being dumped into the atmosphere during future work since that's what's allowed with INEXPENSIVE R134a.

Not necessarily, but far from a bad idea. But since the design engineers often consider the engine & transmission as one package, the firmware may have some integration aspects that require a "same year" switch of both engine and transmission. Certainly worth checking into, given that even within a single MY's production "running" changes are often made.

#1. yes, absolutely. Run "finer", probably. #2. Yes, lower emissions and more HP due to evolutionary improvements. #3. The same thing as the original engine unless you swap in the new engine's "matching" ECU. #4. I wouldn't bother. But what was wrong with the '90 engine that made it not repairable?

Agreed, seconded.

You can use an adapter with a bi-pin halogen bulb to improve the trunk lighting but I have no suggestion for alleviating the safety problem of owning/driving a FWD vehicle on an adverse. slippery, roadbed surface.

Due to the FLAWED, horribly UNSAFE climate control design and utterly UNSAFE and therefore USELESS TC my '92 LS400 gets an 8. I guess since my '01 AWD RX300 shares the same problems plus FWD torque biasing it must get a 6. I'm current waiting for the RX series to get the DFI engine and the Atkinson Cycle. VVT-i....Small I for "small" intelligence. A truly "intelligent" Variable Valve Train would use the Atkinson cycle to extend FE up to 20% except for at or near WOT acceleration.

The only reason I can think of for the electrical coil inside electro-magnetic clutch to blow a fuse is an internal short, which can be deteced with a simple ohm meter, provided it's not intermittent. But since that would be a rather unusual fauilure I would check first for a chafed, shorted, shorting, wire from the control relay to the A/C clutch, much more common failure IMMHO.

I think he's talking about the seals inside the valve springs that prevent oil, mostly, from flowing, getting, down into the valve stem area and therefore slowly leaking around the valve guide into the combustion chamber.

Simple, just take it to GoodYear or FireStone, like your dealer, they'll know when your ball joints need replacing. Okay, your ball joints may actually need to be replaced. But replacing ball "faulty" joints has long been a favorite ploy of automotive service shops. There is no way, method, feeling, absent the wheels finally falling off, for the owner to know when the ball joints are too worn. Additionally these service shops are well, VERY well, aware of the concern they can cause by stating that ANY part of the car's stearing control is failing. Not a good answer but the only good answer is to go to a shop that doesn't need or want your money. Introduce yourself to that shop's service manager tomorrow morning as you wash your face and comb your hair.

"..it would hesitate when pressing on the gas and seemed to be misfiring. Forget the plugs and wires and concentrate on replacing or adjusting the crankshaft position sensor. "misfiring..." triggering ignition at the wrong point...poor or intermittent sensor output. "to my surprise the car did not move..." Absent a reliable input sensor source of actual engine speed the transmission will NOT shift into ANY drive gear. The transmission ECU "thinks" the engine is turning too far below idle and would be likely to stall with a shift into a drive gear.

By 1993 the LSes brakes had been upgraded twice as a result of the problems you just had. If you often travel down that winding road then I would seriously consider upgrading the brake system, new rotors, calipers, to at least a late '92