stirfryboy

My 1999 ES300 is having some electrical issues, won't last more than 2 days on a charge without the battery dying since I purchased it. Today I finally got around to do a parasitic drain test. ECU-B is drawing 75 mA. So, I pulled the fuse. When I started the car up, ABS light was on, shift lock didn't work, and the CEL was on. Put the fuse back in, the SRS light is blinking.

Speedometer doesn't work, code is P0500. The engine and transmission have about 45-50K on them, pulled from a 2001 ES300. The car has 156K on the body.

Ideas? Thoughts?

stirfryboy

No one? Bump

Update time, I found that the driver's seat memory button "SET" was stuck on. Cleaned it up, hopefully won't be draining the battery anymore.

Now, I've spent 2 hours looking for the speedometer sensor. I can't find it. I've undone the air box, battery, cruise control module, traced all the harness wires going to the transmission, and I'm frustrated.

Can anyone help?

tomf

The speedometer sensor is located underneath the air box. There are two identical sensors. This the the part
Follow this link https://www.clublexus.com/forums/rx-...ode-p0500.html . Look at post 3 for a picture of where the speed sensor is located. The one you are interested in is labeled 2. The picture is from an RX but it is the same in the ES.

Sorry I can't help with your electrical problem.

stirfryboy

Some are saying that the sensor to check is under the battery tray. Some are saying that the sensor to check is further back from the starter. Both of the sensors I have cleaned with electrical contact cleaner and put clean ATF on, and put back in. The sensor #2 is the counter gear sensor. The Sensor #1 is the input speed sensor. Transmission shifts fine. I bet it is either a wiring integrity issue or a wheel speed sensor. A faulty wheel speed sensor wouldn't make the speedometer not work correct?

Next steps are to pull ABS codes manually, then reset ABS computer. If it comes back, then can narrow it down more. I will check resistance in both speed sensors. If > 560 <680 ohms, they are good. One post in the RX DIY P0500 said his was 63x ohms, both were good.

tomf

Probably not, but it probably depends on the signals that the sensor is outputting. When I had this problem, the right rear tone ring disconnected from the spindle. Thus the information the sensor was outputting caused the ECU to issue the P0500 and stop the speedometer from working.

Do you have any other symptoms?

stirfryboy

Thanks for replying. No other symptoms, including transmission shifting issues which makes me think the transmission speed sensors are working fine. This transmission has 50K miles.

Your description causes me to think about if I have a bad wheel sensor, those have 156K on them. If a wheel sensor wasn't reading and your speedo wasn't working correct?

tomf

My sensor was working but because the tone ring was (sometimes) rotating independently of the spindle/wheel the data it was sending to the ECU was bogus. I suppose the data was so different from the other inputs that the ECU was programed to disregard all speed data and issue the P0500 and stop the speedometer from working. My speedometer read zero.

Have you had any work done on the wheels, or hubs or bearing that might have caused the problem?

Is your ABS working?

stirfryboy

Gotcha, makes sense. No, the ABS is not working, light is illuminated on the dash. Tested both transmission speed sensors, they are good, measuring 620 ohms each.

tomf

Have you checked your abs error codes? That should give you a starting point.

stirfryboy

I was just doing that. I have a Denso ABS pump. I removed the short jump wire, then used a paper clip to jump E1 and Tc. My SRS light flashed a 48, but no ABS light blinking. Tried to reset it by pumping the brakes 8 times in 3 seconds, no response of flashing ABS light. I know the light works, it's on without the E1 to Tc jumper. I removed the ABS computer, took a look inside to find no evidence of burnt components. Main ABS fuse looks good. Violet and white wire to E9 on ECU looks good and intact.

I'm not sure what to do now??

Do I have a bad instrument cluster?

mmatheny

Are you saying that the speedometer gets its input from the ABS tone ring?? That is absolutely strange!

stirfryboy

Well, an update. I'm feeling retarded

When I was doing the parasitic drain test, I pulled the ECU-IG fuse under the dash. I put it back into a dummy spot, and not back into the correct location. Put the ECU-IG fuse back in the correct location and everything works.

Thanks for everyone's help.

tomf

No I'm guessing the ECU takes inputs from all its speed sensors and does some sort of comparison. Then based on its programing takes some action. For instance if a wheel sensor isn't reporting anything the ECU could assume it's a bad sensor and just ignore it as it relates to the speedometer. In my case, because the tone ring was rotating independently of the wheel, the sensor was probably reporting random speeds, some being higher and some being lower than the actual speed. Perhaps under those conditions the programmers decided it was unsafe to report any speed to the speedometer. Therefore it set P0500 and turned off the speedometer as well as set abs error code 11 and 33. This is pure speculation on my part because I have no knowledge of the internal programing of the ECU.

tomf

Glad you figured it out.