I've been chasing this problem for a few months now and I'm at a loss now.

Here are the codes and info AutoZone scanned for me.

C0210

Right rear speed signal malfunction

C1223

ABS Malfunction

P0174

I've cleaned the MAF, checked for vacuum leaks, replaced the gas cap, replaced the right rear wheel speed sensor, inspected the reluctor/tone ring (no issues), replaced the air filter.

I'm at a loss what else to do or check other than taking it to a mechanic. I'm not scared to do almost any DIY, I just don't know what else to check.

Everything I've read pointed to the rear speed sensor or the reluctor/tone ring.
I inspected the reluctor ring for cracks and/or looseness. It was clean and tight in place, no movement. First I cleaned the speed sensor good and replaced. Didn't help.
Next I replaced the speed sensor with a new one. Didn't help.

After resetting the codes (or lights) they come back on the second time I drive the RX.

Please - any more suggestions or help before I burn this thing?

 

This video covers the P0174:

 

Thanks max.

What I really don't understand is why ALL of these lights came on at the same time.
It could be coincidence, but not likely.

Wheel sensor and lean fuel mixture???
The lean fuel mixture would probably cause the CEL and the speed sensor cause the VSC and Trac Off lights, but all at once?

And remember, the ABS light is NOT on.

 

There are different problems you are having and the visual indicators are messing your thought process. Live monitoring of data can help you immensely, instead of a static read at the auto-part store. You have to be skilled at interpreting the live data. If you post the live data maybe some one can assist you [I can tell you it wont be me].

You have a brake issue (or at least the computer think there is). I would leave that alone for a while.

You have EFI issue which needs attention. The important clue you have is that is on ONE bank so chasing something common is useless [gas cap and MAF]. If I am not mistaken your error code is on bank one. So you need to check the pcv and vacuum piping. Safe carb/throttle body cleaner spray around the hoses will tell you if there is a leak. If the pcv has not been changed, it is worth few dollars [just be careful with the grommet]. Then trace through the Oxygen sensor. If you have 150k miles, it may be worth changing it.

I usually am not in favor of throwing parts, but when other things have been tried, one has to strategically use this approach.

How good is your bank1 valve cover seal? All Toyota/Lexus need retorquing around 100k miles and if that does not work, one has to replace the gasket.


Salim

 

I also thought they would be very different issues, but all 3 lights came on at the same time.
This makes diagnosing the problem harder to think of what may have caused it.

The brakes and ABS system are working fine. The computer may think there is a problem, but I have not noticed anything wrong.

The RX now has about 125k, so I'm sure there are items that are in need of replacing.
I did check the PCV. It was clear, but I guess for $5 I can replace it. (it's the screw in type)

What do you mean to - "then trace it through the oxygen sensor"?

I have an OBD2 scanner that logs data, fuel trims, etc. if someone could interpret them for me.

Thanks

 

Couple of things:
Brakes... the system does think there is a problem, that is why you get the code. You may not have ABS or traction control.

Trace Oxygen Sensor means leaks, wire(s) connectors etc.

If you have the data then please post and lets see if some one can help you.

Salim

 

As for the brakes, the ABS works, I've tried it on a wet road and slamming on the brakes.
I'm not sure how to test the VSC and I don't reallt want to take a curve at 50mph to see if it works.

I'll get the freeze frames with the data and post dropbox link.

thanks

 

Sometimes low brake fluid at reservoir triggers the VSC and ABS. Top off the brake fluid reservoir.

 

I've been reading about the CEL, VSC, Trac Off lights for several months now on this forum and around the internet. The ABS light is NOT on, so it makes things harder to find.

My check engine light appears to be a lean fuel mixture because of a vacuum leak, PCV, 02 sensor, fuel filter or something. Must be coincidence that they all came on at the same time.

I have not found one single post where this problem has been diagnosed as the failure.
Some say it's a speed sensor, some say MAF, PCV, ABS Module, some say air filter, fuel filter, etc., etc. etc.
It seems that this is not a once in a while problem, but happens a lot.
I guess I'll be off to a mechanic for him to guess at the problem for $$.

It is probably something I could fix, but don't know WHAT to fix.

 

Did it happen after oil/air-filter change? Happened to me years ago, turned out the tech pulled the air-filter housing too much, he unplugged the vacuum hose connected to it for the EVAP system, causing all 3 lights to turn on at the same time. I drove it like that for a few years, but one time decided to try and get to the bottom of it, and that's what i found out, it was the damn hose under the air-filter housing under the hood.

I tried resetting the codes, they came back every time... Once I reconnected the hose, all codes/lights were gone. Never experienced any issues driving this way.

 

No, just while driving. I did have a K&N oiled and re-useable air filter, but I removed it and went back to the standard paper drop in filter.
I also removed the whole air filter box and boots looking for vacuum leaks or torn rubber hoses, etc. No Luck.

Are you talking about a vacuum hose that connects to the bottom of the air filter box?
Would you happen to have a pic of the location?

But thanks, I have read that that hose is a common problem coming off.

 

Have you had the rear abs sensors checked? Sometimes they get excessive rust buildup and the abs can activate intermittently on normal braking. That doesn't explain the P0174 but hopefully will help out with the abs/ traction codes.

 

Yes, at the bottom of the housing, there's a rubber hose connected. I don't have a picture, but you can't miss it. Did you inspect yours? maybe it's cracked and vacuum is leaking?

 

Do you mean the one that comes into the bottom side of the air box? (not actually into the bottom)
Yes I made sure it was connected. I'll check it again for cracks.

Thanks for the suggestion.

 

VSC Trac off lights. If your vehicle is older like mine then this is a common occurrence when the OBDII code checker has been used. I am not going to try to explain why it happens because it is lengthy but I will tell you how to reset the lights.
If these lights came on after the code checker was used, do the following.
Take a wire, paper clip etc and short pins 4&14 on the OBDII connector. Turn the key to the key on, engine off position. Note the VSC light flashing rapidly. Turn the key off, remove the wire and go drive.
The lights should stay off.