Strange VSC/Brake/ABS light
#18
Driver School Candidate
Join Date: Nov 2014
Location: California
Posts: 24
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#20
Well seems like my problem is stemming from an Engine code. I checked with the Techstream clone again today, and I'm getting code p0500 (speed sensor). I cleared the code, and drove down the street, code came back on instantly. Left my generic code reader in, and after awhile, the same deal.
Cleared it, and it was good for a few minutes and bam.
Anyone got any idea? The actual speedometer works still though
Cleared it, and it was good for a few minutes and bam.
Anyone got any idea? The actual speedometer works still though
#23
Lexus Champion
iTrader: (5)
Yeah mine was the front right wheel. Took it to lexus. They said it was the wheel speed sensor. Replaced that, didn't work. Said they needed a new hub becuase they needed to match up (sensor and hub). Didn't work. Ended up digging deeper and it was the ABS ECU. And it was expensive, so hopefully yours is just the sensor
#24
Youch, ABS ECU fix it?
I used the techstream again, put her on the rack and checked the data on the speed sensors.
VSC was off, so no traction control anyway. Put her in drive, and gave her some gas while I monitored the rear speed sensors and the speed sensor, all three were dead on. At that point, I had my dad spin the front wheel by hand (and he got it up to an impressive three MPH), one by one, and they all showed.
At this point I have no idea what else it could be
The thing that's killing me is that it's showing a speed sensor code (p0500)
I used the techstream again, put her on the rack and checked the data on the speed sensors.
VSC was off, so no traction control anyway. Put her in drive, and gave her some gas while I monitored the rear speed sensors and the speed sensor, all three were dead on. At that point, I had my dad spin the front wheel by hand (and he got it up to an impressive three MPH), one by one, and they all showed.
At this point I have no idea what else it could be
The thing that's killing me is that it's showing a speed sensor code (p0500)
#26
Tech Info Resource
iTrader: (2)
I did some digging into this. The speed signal is generated by the wheel sensors in the rear. They talk to the skid control ECU. The skid control ECU sends this data to the combination meter to run (primarily) the odometer and the speedometer. The signal is passed through to the ECM. P0500 means the speed signal is not getting to the ECM. So, if you are seeing what appears to be the correct speed and mileage indication on the odometer, there is an issue with the speed signal getting to the ECM. The troubleshooting tree for this is definitely not for the faint of heart as it calls for replacing ECUs like they are free.
Honestly, I would suspect a bad connection in the wiring harness before I would suspect one of the ECUs. Once an electronic device survives infant mortality, it really takes considerable abuse to make it fail. Wire connections are not nearly so robust, and I've had an experience with a connection at the ECM failing because the tiny little petal inside the connector on the wire end didn't quite work below 50F, but connected just fine as soon as the cabin temperature got over 50F.
This failure sounds a little more cut and dried, but I would not put it past a bad connector on the wire end of the harness, especially since the tool (although not a genuine Techstream tool) is indicating the wheel sensors are all working.
Honestly, I would suspect a bad connection in the wiring harness before I would suspect one of the ECUs. Once an electronic device survives infant mortality, it really takes considerable abuse to make it fail. Wire connections are not nearly so robust, and I've had an experience with a connection at the ECM failing because the tiny little petal inside the connector on the wire end didn't quite work below 50F, but connected just fine as soon as the cabin temperature got over 50F.
This failure sounds a little more cut and dried, but I would not put it past a bad connector on the wire end of the harness, especially since the tool (although not a genuine Techstream tool) is indicating the wheel sensors are all working.
#27
I just looked over the email and jumped right in.
Cluster isn't too bad to take out, and neither is the ECU.
The book tells you check resistances from ECU Plug A5, and Combination Meter (Cluster) J34.
Measured resistance, and it's under 1 ohm, at the end of the trouble shooting it says "Replace ECU".
After it tells you to check each of those pins to body ground, and it should be ABOVE 10 ohms. And at the end it says "Replace Combination Meter".
My wiring tested good on both. I think it's along the lines of the ECM. The car had the o2 sensor bypass box (I just saw it today checking out the ECU plugs). And when I first got the car the fuse for the OBD 2 port was blown. I replaced it, and had a check engine light, but the light no longer illuminates, but I can still check with the OBD 2 port.
So who knows, maybe it's both?
Cluster isn't too bad to take out, and neither is the ECU.
The book tells you check resistances from ECU Plug A5, and Combination Meter (Cluster) J34.
Measured resistance, and it's under 1 ohm, at the end of the trouble shooting it says "Replace ECU".
After it tells you to check each of those pins to body ground, and it should be ABOVE 10 ohms. And at the end it says "Replace Combination Meter".
My wiring tested good on both. I think it's along the lines of the ECM. The car had the o2 sensor bypass box (I just saw it today checking out the ECU plugs). And when I first got the car the fuse for the OBD 2 port was blown. I replaced it, and had a check engine light, but the light no longer illuminates, but I can still check with the OBD 2 port.
So who knows, maybe it's both?
#28
Here's an update. I purchased a cluster from another member and stuck it in, and still the same issue. I'm a bit pissed off about it, since he said the needles were good (which mine weren't) so I was going to keep it anyway.
however, when I got it plugged in, the needle lights are dim. Sent him an email with pictures, without any reply. Went ahead and went to a paypal claim anyway. Good thing about claims is you can always cancel it, but it takes forever to get it started.
I plan on leaving him feedback pretty soon, well once this is all situated anyways.
But so cluster didn't fix the issue, gonna move on to the next thing (ECU) which I really don't want to bring it down to Lexus to have them charge insane amount of money reprogramming it. Does anyone know if I can purchase an ECU from a different IS (ISx50) and get it reprogrammed to the F?
however, when I got it plugged in, the needle lights are dim. Sent him an email with pictures, without any reply. Went ahead and went to a paypal claim anyway. Good thing about claims is you can always cancel it, but it takes forever to get it started.
I plan on leaving him feedback pretty soon, well once this is all situated anyways.
But so cluster didn't fix the issue, gonna move on to the next thing (ECU) which I really don't want to bring it down to Lexus to have them charge insane amount of money reprogramming it. Does anyone know if I can purchase an ECU from a different IS (ISx50) and get it reprogrammed to the F?
#29
Tech Info Resource
iTrader: (2)
have you checked wire continuity with the cover off the ECM? If it were mine, I'd check to be sure it isn't the connector pin in the plug connecting the ECM. I've seen this before.
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