Lexus ES 300 OD Problems

dsmcaseydsmcasey Member Posts: 4
edited July 2014 in Lexus
*I searched and can't find the answer.

Hi Everyone,

I just bought a '99 ES 300 with 106k miles. The car is in great shape and I had it checked out by the family mechanic when I bought it. His only complaint was that the 100k service had not been done, so I got that taken care of. Now that I've driven it 500 miles I've noticed two things:

1 terrible gas mileage
2 It never, ever shifts into Overdrive

I don't have any check engine lights showing on the dash, but the car turns about 4k rpms going 70mph down the freeway. I can turn the OD button on or off going 70 down the freeway and nothing changes, the car doesn't shift. I have also paid close attention to at what RPM the car shifts on lower gears. Oddly enough, the car shifts into second gear at 4400 RPMs. This seems really low to me. I've also counted the shifts the car does when accellerating to highway speeds and I count three shifts. So either I have a one of a kind 3spd or something is wrong here! So, how much work + money am I looking at for the repairs and can someone point me in the right direction?



  • wwestwwest Member Posts: 10,706
    Have you verified that the CEL bulb is actually functional..??

    Unplug the MAF and see if that results in a CEL.

    New timing belt was incorrectly "timed"...??

    Is the engine coming up to FULL operational temperature?? Has some past owner removed the thermostat..??

    Or it could be that the engine is so "tired" it cannot produce the torque level required of OD in that low RPM range. For this latter, try a few tanks of premium after reseting the engine/transaxle ECU.
  • dsmcaseydsmcasey Member Posts: 4
    Just checked...the CEL light is NOT functioning. I read on the internet that it could be a temperature sensor on the transmission that is malfunctioning so I went and had the codes read on the car at autozone. Here are the codes I got:
    P0172 "Fuel System in Bank 1 too rich"
    P0325 "Knock Sensor 1"
    P0330 "Knock Sensor 2"
    However, I did get the injectors serviced and had a tune up performed on the car as part of the 100k maintenance. So, I think these codes may be thrown from whenever the injector testing was done. How can I reset the codes and see if they come up again? Just disconnect the battery for a few minutes?

    Thanks for the replies!!!!
  • wwestwwest Member Posts: 10,706
    Go back to....

    "I just bought a '99 ES300 with 106k miles...."

    There is a good chance, IMMHO a REALLY good chance that the CEL bulb was intentionally disabled by the seller.... I would check and see exactly what the CEL bulb failure "cause" was/is.

    Bulb simply removed would equate to intentional fraud by the seller.

    What I do not, cannot understand, is just exactly how someone did the 100,000 mile service, tune-up and injector cleaning all without noticing that codes were being "thrown" and the CEL bulb was not working.

    Sounds as if you may have been "had" by both the seller (dealer..??) and whoever did the 100,000 mile post-purchase follow on work.

    If the seller ready wanted to "hide" the fraud they might remove the bulb, apply ~30 volts to "blow" the filament, and then re-install the bulb. I have even heard of instances wherein traces were cut to disable the bulb's CEL functionality and then the bulb cross-wired to another function so the bulb appears to work normally in test mode before the engine is started.

    Looks like your seller may not have been a very "bright" bulb, PUN fully intended. If you should find the bulb missing I would immediately hire an attorney.
  • wwestwwest Member Posts: 10,706
    Those codes, that combination, would seemingly indicate a bank 1 fuel injector closing slowly or never fully closing.
  • pgoodpgood Member Posts: 3
    so what was the final outcome or "fix" for this problem? I have the exact same problem on the same vehicle. Is this issue common for the Lexus ES300? HELP!!
  • wwestwwest Member Posts: 10,706
    If the OD lockup clutch has degraded to the point it slips the ECU will soon "learn" that and stop using OD. The other possibility is that the engine itself is so degraded it cannot produce enough torque in the OD road speed range that OD can be used.

    You can test the above theories by filling with 92 octane, disconnecting the battery to erase the previous "learned" parameters and see if the ECU will then use, or attempt to use OD. If the clutch is failing the ECU will soon stop using OD again. If the engine is degraded the ECU may use OD again until you switch back to regular.

    You might also want to look into the possibility that the engine is degraded due to a clogged exhaust due to catalyst structure failure.

    If the 99 had an ATF thermistor to prevent use of OD until the fluid was warmed up the thermistor may have failed.
  • pgoodpgood Member Posts: 3
    The malfunctioning ATF thermistor makes sense because the car would begin shifing into OD once the engine/trans was warmed up in the winter (last year). Is the thermistor located outside of the transmission? Should I have a mechanic do the work? How much will it cost me?

    Let's assume that the OD problem is resolved by replacing the thermistor. I still have the CEL and Traction Control lights to deal with. I had the ECU code read...P0330 "Knock Sensor 2". I was told by the Lexus service folks that the Traction Control is frequently "shut down" by the ECU when a CEL is activated for a prolonged period of time. Is this true? What should my next steps be? I'm hesitant to take the car to the Lexus dealer again because they were not able to resolve my problems by changing out parts (rear injector bank) which cost me $1200. It seems they read the codes, then change out parts without resolving the root cause. Thank you very much for your assistance.
  • wwestwwest Member Posts: 10,706
    Why did you not disclose "all this" at the very beginning...??

    The engine/transaxle ECU WILL NOT use OD if the engine performance is KNOWN to be degraded. A knock sensor 2 code is a clear indication of degraded engine performance. And a VSC, Trac fault code is a default condition anytime there is a CEL. Fix the engine problem and the Trac code will also go off.

    And keep in mind that the knock sensor code may not mean the problem is with the knock sensor itself.
  • dsmcaseydsmcasey Member Posts: 4
    Wow...This was an old post...But, I got the problem resolved. I reset the ECU after it threw the codes for a second time. Turns out it was the knock sensors and the CEL was just malfunctioning. The car WAS in limp home mode. I was surprised the tranny didn't shift harder considering it was in LIMP mode. But, anyway, I got both knock sensors and the wiring replaced (and got the CEL fixed). My wife's uncle is a retired mechanic and he did the work at a discount. It was still quite costly though for all the parts. Regardles, after the sensors were replaced the car went into overdrive and drives fine. It actually drives tons better. I was amazed at how much of a difference it made.

  • pgoodpgood Member Posts: 3
    Casey, Thanks very much for the information. Do you know how difficult it was to replace the knock sensors? I may try to do it myself if it's not a huge job. I received a price of $155 each for an aftermarket sensor....not sure about the wiring. Please share more information if possible.

  • wwestwwest Member Posts: 10,706
    Before you spend money I would reset the CEL by disconnecting the battery and put in a FULL tank of high octane. It is entirely possible the engine knock was a transient one time event.

    If the CEL returns after a few drive cycles what have you lost, 10% extra on a tank of gas...??
  • dsmcaseydsmcasey Member Posts: 4

    The knock sensors are a VERY common problem with this vehicles (and other lexus/toyota vehicles of the same year). I found the part numbers on the clublexus site by searching in the forums. There is also a post about how to change them out and it includes pictures and step by step instructions. It's not a terrible job but it does involve removing the intake manifold, which can be a pain. I got the sensors from carson toyota for less than what you are paying. Also, the WIRING is USUALLY the culprit, not the sensors. BUT, to get to the wiring you have to take off the manifold, and while you're in there you might as well replace the sensors sense there's no gaurantee that they weren't the culprit as well.

  • lovelearnlovelearn Member Posts: 3
    1992 ES300 intake manifold is secured by two 8-mm hex Allen-wrench-type cap bolts and by two conventional cap bolts. The Allen-wrench-type cap bolts were selected because the intake manifold casting passes so close to those two bolts that it did not leave sufficient room to attach a conventional external socket wrench. I bought both factory shop manuals for this car which told me these cap bolts take an 8-mm hex Allen-wrench tool and are supposed to be torqued to 32 or 33 foot pounds, depending on which place in the manual you are reading. I applied PB Blaster and let the bolts sit and soak for about 8 hours before trying to release them. Then, before applying torque, I struck the 3/8" driver socket into the hex hole to make sure the tool was fully bottomed into the screw head hex-hole, and to "disturb" the threads which may enable breaking them free.

    Both of these cap screws have failed to rotate but their hex driving holes have rounded out from the hex driving rotating a full 60 degrees! I've tried hamming a chisel into the cap screw's side to apply off-axis rotational impact shocks, but have only pealed away part of the outer cap's metal.

    I'm not eager to weld allen wrench 3/8" drive tools into these locked-in-place cap screws. But that may be next. I'd estimate that I pulled about 100 foot pounds on each of these before their metal hex holes deformed enough to allow the wrench to rotate without rotating the bolt.

    Any suggestions? I've got to wonder if some idiot spun those in with an air wrench to have caused them to become so stuck.

    Any help would be appreciated. Just need to replace the rubber gaskets around the 3 rear injectors because one has started leaking enough to smell gas when driving.

    Car has about 230,000 miles, 5-speed manual, and given very few problems, burns no oil. Dash light fade out as others have described, power window problems which are not "deal breakers" and can be repaired by competent home mechanics in driveway, AC freon leak after 200K on original charge, still gets over 30 mpg during highway travel, center section of harmonic balancer released from outer section, causing alternator belt to be driven slower than designer intent resulting in intermittent alternator dash charging system indicator light flicker, yet it keeps battery charged so it always starts, and the front shock top mount rubber mounts started making alarming noises, but turned out to be an easy quick driveway replacement fix with improved designed replacement parts.Oh yes, every 90 days spend 60 seconds per side cleaning the headlamp covers with polish because they become dull for some reason. On balance, an excellent car in my opinion.
  • hiflyer1hiflyer1 Member Posts: 1
    We had the same problem with our 1995 es300 with 275,000 miles .. took it to a reputable trans shop . they checked out all the electrical/computer and said we needed a $2,500 overhaul .. we used the info here .. filled up with high octane (we had been using regular) burned 3/4 of the tank .. disconnected the battery for 10 minutes and to our surprise it has been shifting into and out of overdrive like a charm. Thanks to who ever figured this one out.... :)
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