94 ES. Hard shifting, no O/D. Code PO500 & PO720
04-16-09, 09:17 PM
#16
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This is the od switch circuit. You state that the od light never goes out, just bright to dim.
I would first disconnect the switch. Does the light go all the way out, or just dim? if it goes all the way out, your switch is hosed, get another switch.
If the light stays on dim with the switch out, then disconnect pin E7 at the ecm. Does the light go out now? If the light stays on, you have a short somewhere in your harness. Try to find it because there are going to be other issues down the road.
If the light goes out, it sounds like the ECM is hosed. You can verify that the grds are good to the ecm, but since the engine is running well, it will probably be the ecm.
04-16-09, 09:31 PM
#17
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Attachment 142607
This is the od switch circuit. You state that the od light never goes out, just bright to dim.
I would first disconnect the switch. Does the light go all the way out, or just dim? if it goes all the way out, your switch is hosed, get another switch.
If the light stays on dim with the switch out, then disconnect pin E7 at the ecm. Does the light go out now? If the light stays on, you have a short somewhere in your harness. Try to find it because there are going to be other issues down the road.
If the light goes out, it sounds like the ECM is hosed. You can verify that the grds are good to the ecm, but since the engine is running well, it will probably be the ecm.
This is the od switch circuit. You state that the od light never goes out, just bright to dim.
I would first disconnect the switch. Does the light go all the way out, or just dim? if it goes all the way out, your switch is hosed, get another switch.
If the light stays on dim with the switch out, then disconnect pin E7 at the ecm. Does the light go out now? If the light stays on, you have a short somewhere in your harness. Try to find it because there are going to be other issues down the road.
If the light goes out, it sounds like the ECM is hosed. You can verify that the grds are good to the ecm, but since the engine is running well, it will probably be the ecm.
Great job and thanks! Looks like you're the man to talk to, I really appreciate it. And I know what I'm doing so keep it coming.
04-16-09, 09:49 PM
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Attachment 142617
Page3, I am not sure if you mean that the od light is staying dim, or the other light. But I have uploaded the diagrams for both, so you should help you narrow this issue down.
Page3, I am not sure if you mean that the od light is staying dim, or the other light. But I have uploaded the diagrams for both, so you should help you narrow this issue down.
04-16-09, 09:52 PM
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You answered my question while I was uploading the other pics. I really don't like the upload limits they place on files here. Most of the things I try to upload are too large. I had to break this up into 3 different parts.
04-16-09, 10:00 PM
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Oh ok, I'll look into it. The ECT light has the problem, the OD light is fine, it just doesn't shift the trans into OD. So I have no OD at all. I'm gonna pop it out and check it with a multimeter. I don't mind being stuck in ECT PWR mode full time, just figured it factored into this whole problem. I really just need OD back. Thanks.
The other thing would be to try to borrow a different scanner. I have a MT2500, while I friend of mine has a genisis. I have read the same car with both and sometimes get different results.
04-16-09, 10:03 PM
#24
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Like, can you tell me these things with these schematics? Ok, where does the OD switch go and in what order? Like, ECM, dash light, then trans connector? And will it tell you which trans connector and pin it controls? Is it a voltage signal? Can a bad O2 have anything to do with this? I was reading that the coolant temp sensor can in these ES300s.
What part of TX are you located?
04-16-09, 10:08 PM
#25
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[QUOTE=GEORGE_JET;4443597]Try to get the ECT light to work properly. Since you do not have any codes coming up at this time......QUOTE]
Oh no, all the codes came back today. I only have one scanner, I'll tell my mom to drive it to Auto Zone and get some there.
Oh no, all the codes came back today. I only have one scanner, I'll tell my mom to drive it to Auto Zone and get some there.
04-16-09, 10:11 PM
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I am a little south of Austin. PM me with your email. I can send you some more files that will help you out. Most of the files are less than a couple megs, but there are some small limits on the files that can be uploaded here.
04-17-09, 07:13 AM
#28
Lexus Champion
If the fluid is messed up [has a burnt look or smell] replace it and the filter [do not do flush].
Reset codes
If the connector hasn't been taken off, take it off, inspect, if rusty[oxidized] or moist, then replace or clean and put dielectric grease in there.
Check the ground cables and battery strength too, sometimes, weird problems with the ECU or PCM can come from that, the sensors need a certain reference to work.
Reset codes
After that, if the car is changing it's shifting habits, as you have indicated, this is likely a transmission problem [with the internals]. See if the shifter works while you're driving. you might not be comfortable with that, but see what happens if you drive in second gear [keeping the engine speed below 3500 RPM as a general guide]. then, move selector to what normally would third gear [perhaps, on this car, "D" or Drive, but with ''O/D" or Overdrive electronic button set so the overdrive is disabled]. see what happens. if the thing does it, but in some weird fashion, then the PCM is not seeming to malfunction.
Check the vehicle speed sensor output [square wave] with a multimeter or oscilloscope. should have a certain pattern to it. it's covered , most likely, in the factory service manual [try the '97's or even the '93 to cross reference]
If you get this far, then, yeah, very likely a problem with the transmission, the parts inside could be slipping and the transmission is dieing trying to compensate and saving itself it's best despite the fact that you and your mommy keep driving her around. probably soon it will try to drive with limp mode in second gear if it is not already doing that. the shaft in the transmission and bands and clutch packs work together with the torque converter, but if they can't, or one of them is failing, then the transmission parts work at the wrong speed, causing the PCM to freak out noticing that it's slipping or has insufficient pressures.
STOP if you got at this point, you ought to have an expert with toyota/lexus transmissions work on it and give an estimate [to really tell what's wrong will require a lot of labor, so the truthfully full diagnosis will not be so cheap].
Reset codes
If the connector hasn't been taken off, take it off, inspect, if rusty[oxidized] or moist, then replace or clean and put dielectric grease in there.
Check the ground cables and battery strength too, sometimes, weird problems with the ECU or PCM can come from that, the sensors need a certain reference to work.
Reset codes
After that, if the car is changing it's shifting habits, as you have indicated, this is likely a transmission problem [with the internals]. See if the shifter works while you're driving. you might not be comfortable with that, but see what happens if you drive in second gear [keeping the engine speed below 3500 RPM as a general guide]. then, move selector to what normally would third gear [perhaps, on this car, "D" or Drive, but with ''O/D" or Overdrive electronic button set so the overdrive is disabled]. see what happens. if the thing does it, but in some weird fashion, then the PCM is not seeming to malfunction.
Check the vehicle speed sensor output [square wave] with a multimeter or oscilloscope. should have a certain pattern to it. it's covered , most likely, in the factory service manual [try the '97's or even the '93 to cross reference]
If you get this far, then, yeah, very likely a problem with the transmission, the parts inside could be slipping and the transmission is dieing trying to compensate and saving itself it's best despite the fact that you and your mommy keep driving her around. probably soon it will try to drive with limp mode in second gear if it is not already doing that. the shaft in the transmission and bands and clutch packs work together with the torque converter, but if they can't, or one of them is failing, then the transmission parts work at the wrong speed, causing the PCM to freak out noticing that it's slipping or has insufficient pressures.
STOP if you got at this point, you ought to have an expert with toyota/lexus transmissions work on it and give an estimate [to really tell what's wrong will require a lot of labor, so the truthfully full diagnosis will not be so cheap].
Last edited by llcoolpass; 04-17-09 at 07:36 AM. Reason: spa wring
04-17-09, 07:32 AM
#29
Lexus Champion
from: http://www.2carpros.com/forum/1996-d...-vt233007.html
http://www.2carpros.com/forum/1996-d...-vt233007.html
P0720 Output Speed Sensor Circuit Malfunction
P0500 Vehicle Speed Sensor Malfunction
What does that mean?
Basically this means that the vehicle's speed as read by the Vehicle Speed Sensor (VSS) is not working properly.
Symptoms may include:
* loss of anti-lock brakes
* the "anti-lock" or "brake" warning lamps on the dash may be lit
* the speedometer or odometer may not work properly (or at all)
* your vehicle's RPM limiter may be decreased
* the shifting of an automatic transmission may become erratic
* other symptoms may also be present
Causes
A code P0500 may mean that one or more of the following has happened:
* The Vehicle Speed Sensor (VSS) is not reading (functioning) properly
* There is a broken/frayed wire leading to the vehicle speed sensor
Possible Solutions
The simplest thing to do is to reset the code and see if it comes back.
Next, check all wiring and connectors that lead to the speed sensor. The location of the sensor depends on your vehicle. The sensor could be on the rear axle, transmission, or perhaps the wheel hub (brake) assembly.
If the wiring and connectors are OK, then check the voltage at the speed sensor. Again, the exact procedure will depend on your make and model of vehicle.
If everything looks OK, replace the sensor.
***If the transmission was just serviced, then they didn't do the job right. Tell them to fix it, but I won't pay them any more money...
http://www.2carpros.com/forum/1996-d...-vt233007.html
P0720 Output Speed Sensor Circuit Malfunction
P0500 Vehicle Speed Sensor Malfunction
What does that mean?
Basically this means that the vehicle's speed as read by the Vehicle Speed Sensor (VSS) is not working properly.
Symptoms may include:
* loss of anti-lock brakes
* the "anti-lock" or "brake" warning lamps on the dash may be lit
* the speedometer or odometer may not work properly (or at all)
* your vehicle's RPM limiter may be decreased
* the shifting of an automatic transmission may become erratic
* other symptoms may also be present
Causes
A code P0500 may mean that one or more of the following has happened:
* The Vehicle Speed Sensor (VSS) is not reading (functioning) properly
* There is a broken/frayed wire leading to the vehicle speed sensor
Possible Solutions
The simplest thing to do is to reset the code and see if it comes back.
Next, check all wiring and connectors that lead to the speed sensor. The location of the sensor depends on your vehicle. The sensor could be on the rear axle, transmission, or perhaps the wheel hub (brake) assembly.
If the wiring and connectors are OK, then check the voltage at the speed sensor. Again, the exact procedure will depend on your make and model of vehicle.
If everything looks OK, replace the sensor.
***If the transmission was just serviced, then they didn't do the job right. Tell them to fix it, but I won't pay them any more money...
04-17-09, 07:34 AM
#30
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llcoolpass - are you sure you responded to the correct thread? I see nothing in this thread regarding anyone treating you with "nothing but disdain and mockery" - unless there were some PMs we don't know about.