jaswood

The "best", least expensive, estimates can only be obtained once inspection of the rotors, pads, and overall caliper condition (slide pins, etc.) is completed. Front pads = ~$50 plus labor. Rear pads = ~$40 plus labor. Provided all else gets a "pass" as is often (DIY) the case.

You should keep in mind that you do not have an "Oh *BLEEP*" type of "AWD" system. The RX series, inclusive of the RXh, are all primarily FWD and thereby extemely subject to loss of directional control resulting from the use of to much engine torque, leading or lagging (lagging = regen or compression braking) for roadbed conditions. The instant front, driven wheel, slip/spin is detected the TC, Traction Control, system will assume control, fully dethrottle the engine and begin applying the front brakes, all in order to most quickly return your front tires to a tractive state. While it would be rather nice to have the system, at least initially, quickly apportion a higher level of torque to the rear driveline upon detection of front wheelspin/slip, that is not the quickest way to assure the abilily of the driver to assert lateral, directional control once wheelspin/slip is already present. What you have is a PART-TIME "AWD" system, a pre-emptive, preventative, loss of direction control prevention system. The most likely time, situation, wherein front wheelspin/slip would most likely result is during low speed acceleration, or while turning, turning tightly, and especially accelerating into, during, turning. Those are the ONLY times your RXh's "AWD' system will be automatically engaged and therefore of any real benefit. So... Be careful out there.... Also. You may soon note that your RXh will quickly convert from regen braking to full frictional braking should there be even the slightest hint, a slight bump, slick paint strip, etc, of loss of traction. Most owners report a slight "lurch" forward upon this transition, lasting no more than a few hundred milliseconds provided the recall reflash has been done.

If you start out having accrued a good deal of city stop and go mileage, the condition wherein the HSD system SHINES, stellar FE in comparison to a non-hybrid, then that is EXACTLY what you should expect. Now drive on the highway long enough, enough distance, and the MPG reading will decline very close to the highway average, prossibly even lower than an equivalent non-hybrid. On the highway the HSD system will have very little opportunity for recovering FREE energy via regenerative braking. The ICE will, therefore, be the primary source for restoring the SOC of the HV battery whenever that becomes a requirement. So, on the highway you have not only mostly lost the ability to recover FREE energy, you now must make use of a fairly lossy path for/to recharging the HV battery.

The design should be such that you CAN NOT deplete the SOC of the HV with the HSD switched off, I would be extremely surprised if it were found to be otherwise. So no, the downconverter MUST be disabled with the HSD system switched off. On the other hand the downconverter MUST be enabled whenever the HSD system is "live".

Since the output of the DC-DC downconverter is connected directly to the battery positive post that is no real way to tell from moment to moment. Quite obviously if, at ANY TIME, the 12 volt current load is greater than the downconverter output capability then the battery will be used to make up the difference. But again the downconverter MUST be the primary overall average source of 12 volt power else the SOC of the 12 volt battery would deplete.

My kids are grown, married, and kids, if you call teenagers human, of their own, but I would NEVER allow the vote of a 10 year old to sway my own opinion in this. Additionally, like "whichever-the-wind-blows" Romney, they tend to change their minds 'way too often. Should the new Sienna have the Venza style F/awd system, and even better, with the I4, that's the direction I would go for the most comfortable overall seating arrangement, plus.... Reasonably good wintertime road-handling capability.... Not on a par with the MDX, but worthy.

A bit of a history lesson... Shortly after purchasing, Oct. '91, a brand new 1992 LS400, I discovered that it had a GREAT propensity for SUDDENLY fogging over the interior windshield surface. My immediate reaction, at first, was depressing the PB for defrost/defog/demist mode. More often than otherwise, AMAZINGLY enough, this often made matters worse, MUCH worse. Upon the activation of the defrost/defog/demist mode I often, within milliseconds, found myself with no forward vision as a result of the density of the windshield condensation. This turned out to be the result of a MAJOR design flaw within the NipponDenso, Denso US, automatic climate control design that still exists to this very day. What is happening with your RX400h, automatic mode switch to PREVENT (hopefully) windshield fogging, is a back door approach to solving the actual design flaw. The BEST procedure when one first sees even the slightest bit of interior windshield fogging is to first, IMMEDIATELY, turn the HEAT to MAXIMUM, quickly switch to defrost/defog/demist mode. If the system, as it certain should, does not of itself automatically switch into FRESH airflow inlet mode and HIGHEST blower speed then quickly do so yourself. The results will be twofold. 1.) The extraordinary HEATING of the system airflow will result in quickly, "MOST" quickly, dispersing the condensation via evaporation. That's because the extraordinarily HEATED system airflow will result in the airflow to the windshield having a very low Rh, relative humidity, and will literally act as a SPONGE. 2.) The interior surface of the windshield will be HEATED by the HOT airflow thereby raising the surface temperature well above the previous dewpoint. Now...CAUSATIVE factor(s). Your windshield interior surface began to fog over in the first place due to ONLY one factor. The windshield interior surface temperature declined enough that the dewpoint of the cabin atmosphere was reached. Now you will need to remain mindfull of the need to keep that windshield surface WARMED well above dewpoint, or in the alternative lower the Rh of the cabin atmosphere. The latter can be accomplished by raising the temperature setpoint slightly, and/or continually PURGE the cabin atmosphere via the use of FRESH mode, and possibly even lowering the rear windows very slightly.

Other than providing power for the door locks (unlock) various lighting aspects, power for the hazard flashers in case the HSD system fails, the only reason I can think of is listening to the radio while watching the submarine races. And, it also powers up all the computers prior to starting the hybrid system? Pretty sure I've read that in my service manual somewhere. I also wanted to post something I found in the manual for your opinion Jaswood, but I'm not at home. Could just be bad wording, but I read that all the 12 volt accessories were powered by the battery, which was in turn recharged via the hybrid system. The wording makes it seem that the battery is powering everything and is being kept topped up by the traction battery. I'll post the exact phrase when I get home. There is a SOLID heavy guage wire connected between the positive battery post, the DC-DC down-converter output terminal, and the power distribution fuse "box". If the 12 volt current flow requirement is greater than the down-converter can supply at any given moment then the battery SOC is drawn down. If, on the AVERAGE, the down-converter cannot supply an output current slightly above the level required then the 12 volt battery will end up with a low SOC. Think or a water pump, a pressure tank accummulater, and an open faucet, all connect in parallel with a large pipe. The water pump is sized such that it cannot supply enough flow if the faucet is fully open. But since the faucet is almost NEVER fully open the pump has times when the accummulator can be recharged.

Lexus adopted the Ford Escape F/awd system as of the 2010 MY. F/awd systems of this type, rear diff' mounted electromagnetically actuated clutch, seem to be highly subject to overheating of the F/AWD driveline components. Especially so if the F/awd mode is used/engaged at inappropriate times. The PTO ring/pinion typically overheats, heating the ATF, and the pressure therefrom blows a seal of two. The RX350 has a driver controlled F/awd engagement capability which should NEVER be used except in KNOWN low/marginal traction conditions. Bad enough that the system is always engaged, even in HIGHLY TRACTIVE conditions, during low sped acceleration or when turning tightly or accelerating into, in, a turn. Personally were I to own one of these F/awd systems I would modify the rear clutch circuit such that it would NEVER engaged unless I manually switched it on, which I would only do in KNOWN slippery roadbed conditions.

Oxygen sensors used as A/F mixture control ofte fail at that mileage level, both not far apart is not all that unusual.

Other than providing power for the door locks (unlock) various lighting aspects, power for the hazard flashers in case the HSD system fails, the only reason I can think of is listening to the radio while watching the submarine races.

The reality of the matter is that once the HSD system is "started" the HV battery charging and brake regeneration system is the primary source of 12 volt current flow. Just as the alternator is in a regular car. The DC-DC down converter, HV down to 12 volts, provides the isolation to protect the various components that require only 12 volts. If that failed somehow.......

But it would go "flat" were you to set and listen to the radio with the HSD not "started". This way no one cares if you fully deplete the 12 volt battery. Would it though ? It is a very big battery pack. 288v converted down to 12v will only ever draw nominal current. I think I can state with great confidence that without the HSD system "started" the 12 volt battery will be isolated from the HV battery. Sit and play the radio all you wish all you will discharge will be the 12 volt battery.

Sensor/wiring/connector is open. DSP, Digital Signal Processing, prevents the OAT indication from changing faster that mother nature makes possible. Possibly doesn't even react to an out-of-range, zero ohms, sensor resistance. Try 2800 ohm resistor. Thermistor has negative temperature coefficient, resistance increases with lower temperatures. A/C compressor is disabled when the OAT is below freezing and climate control acts, reacts, as if lots of HEAT is needed.

Oh, I see..."demolished" as in FE, not "roadability". Depending on the type of wintertime driving you expect to encounter the MDX may will be more "economical" in the long run.

At those kind of miles you need to take a hard look at all of the driveline component mounts/cushions, motor mount, rear differential, outer axle suspension points. I wouldn't be surprised if you need an entire set of u-joint bearing also.

Make sure the fuse(s) aren't blown.

They must not have tested the MDX with the SH-AWD system.

Top/right column "bullet" page 271 of the 2006 RX400h owners manual. ** The "Floor/Windshield" air flow mode may be applied automatically, if the outside temperature is below 0C (32F). (more...) In my opinion it would be patently foolish to leave the system in recirc when the system goes automatically into windshield defog/demist mode as above. Page 274 right column, 2nd paragraph... For example, when the ambient temperature is low, the air intake mode may change automatically to the OUTSIDE AIR mode. This is not a malfunction. Vehicles of asian origin use NipponDenso climate control designs almost exclusively. Due to a design flaw originating back in the late eighties vehicles with these systems have proven to be uniquely subject to instances of sudden, spontaneous, windshield fogging. Even with the safety measures taken as above to prevent the onset of windshield fogging the problem seemingly persists.

Because, as a matter of safety, the operational mode of the A/C bears directly on the ability for the system to remain in recirc mode, or in some cases even switch into recirc mode. And be aware that should the system automatically switch the A/C off for one of the aforementioned reasons although it appears that you can over-ride the A/C and switch it back on the indicator will illuminate but the A/C compressor will remain disabled until the causative factor abates. The last time i hit the "A/C" button besides this week during "testing" was probably last October... I've never had to touch that switch unless switching between Summer and Winter months; so if it toggles ON and OFF it hasn't bothered me. The only thing that bothers me is the "inside" vs "outside" air thing. If i tell the car to recirculate inside air, the car should do whatever it has to, to make it work. If that means switching ON/OFF the A/C system, then that's what the car should do. It's the middle of the winter; i don't need any cold air! And i don't remember this issue occurring during summer months... "...summer months..." Unless you interfer with its operation the A/C cooling/dehumidification system will be enabled 24/7. It is only during the wintertime that the system is likely to shut down due to the OAT being below ~34F. The A/C system CANNOT be made functional with the OAT below freezing so the only alternative is to disable the recirculate function and thereby prevent the buildup of moisture, rising Rh, within the cabin.

If you have a VSC fault indication but no CEL then the fault is isolated to the VSC functionality. There are only 2 sensors unique to VSC, the yaw sensor and the steering wheel rotational position sensor. I have seen some indication that should you move the steering wheel to a significant extent with ignition off the VSC fault will indicate until the system recalibrates itsself.

Because, as a matter of safety, the operational mode of the A/C bears directly on the ability for the system to remain in recirc mode, or in some cases even switch into recirc mode. And be aware that should the system automatically switch the A/C off for one of the aforementioned reasons although it appears that you can over-ride the A/C and switch it back on the indicator will illuminate but the A/C compressor will remain disabled until the causative factor abates.

Was that a typo or was backwards intentionally...? Don't ALL modern day systems switch AUTOMATICALLY to FRESH when you activate defrost/defog/demist, or even partial windshield flow...? Ack...lol. Backwards. I mean too clueless to switch from RECIRC to FRESH if the windows start to fog up. Yes, that's my point. The car does it automatically now because most people don't think to do it themselves. Every winter I see older Toyota Corollas and Honda Civics with all the windows fogged up and I can almost guarantee that they are driving around with RECIRC on. "...every winter I see older...don't think to do it themselves.." Maybe, maybe NOT. Asian manufacturers use NipponDenso climate control designs pretty much exclusively. Going back to the late eighties and well into the ninties, mayb even today, these design were quite seriously flawed insofar as defogging windshield/windows and keeping them defogged. NipponDenso designs of that era relied EXCLUSIVELY on the dehumidification capability of the A/C for the task of keeping the cabin atmosphere below the dewpoint of the interior windshield surface. Given that mother nature has full control of the effectiveness of that task it rarely works in certain climatic conditions. To make those systems workable insofar as defogging the windshield and keeping it that way the driver HAD TO KNOW to crank up the HEAT simultaneously with switching to defrost/defog/demist mode. The thing that made that quite confusing was/is that until the cabin temperature was raised to with a few degrees of your temperature setpoint the system would use HEAT and, along with, the A/C. But then there was yet another NipponDenso design flaw that was/is important if you happen to own a vehicle with a fully automatic climate control system. With those systems you had to know about an unpublished aspect of the operation of the system. In fully automatic mode the system, without ANY indication to you, would modulate, linearly modulate, between "fresh" and "recirc" in accordance with certain control parameters. You had to know to follow up with putting the system in "auto" mode and then depress the "fresh" PB in order to lock the system in "fresh" mode. Otehrwise even with the "fresh" PB indicator illuminated the system might be 80% in recirc mode. On a cold winter day, DANGEROUS, that.

There are a few things that will result in the A/C cooling/dehumidification system being shut down automatically. If you are in "recirc" mode when that happens I have little doubt that the system will then automatically switch to "fresh". 1.) If you drive into an area of sub-34F temperature. Note: Driving OUT of a decently warm garage into COLD weather the A/C system switch off a few miles down the road. 2.) If the engine coolant begins to rise toward the point of overheating. NOTE..not actual overheating, just close-by. There might be other causes, those are the ones I have encountered or know about.

Please keep in mind the adverse effect the TOW weigh/inertia will have if you encounter a situation wherein a quick/sudden maneuver or/and panic braking is required. I wouldn't tow anything without having electric brakes for the TOW. And you might find the regenerative braking being a lot less efficient due to the downward force on the rear bumper, less front traction, when slowing/coasting/braking. On the other hand you're not likely to have much use for regen braking on your "tours", highway cruising.