ABS light on along with C0205 code. Installled new ABS sensor, but ABS light still on

[mnalep]

My ABS light was on, and I tried cleaning the LH front ABS sensor. That did not solve the problem, the ABS light on, and a C0205 code, as well as a few others.

So, I put in a new ABS sensor,and took the RX350 for a drive and the ABS, VSC OFF, and Traction warning lights went off before I even got to the end of the block.

So, I thought I had the ABS light problem solved.

Then I decided to run a complete scan with my bluetooth OBD2 scanner (a BLCKTEC scanner) and the c0205 and other braked codes came back on, along with the ABS light in the dash! It's almost like the bluetooth scan triggered the ABS light to go back on! Is that possible? So, I took the car for another drive hoping the lights would go off, again - but not luck. Lights are still back on. The new ABS sensor OHM'd at 1.6 k OHMS, which is supposedly right in the middle of the acceptable range of 1.4 to 1.8.

So, what do I try now?

 

[Ian Schmidt]

Wheel speed sensor codes can also be damage to the wiring or the magnets on the rotor rotting away (especially if you're in the salt belt). If your scanner can show live data, set it to show the wheel speeds, jack up the front of the car, put it in neutral, and spin the wheel while messing with the wires to the sensor.

 

[mnalep]

I believe the OBD scanner can show live data. The car is all wheel drive though, can the wheels be spun by hand on AWD car? I suppose I could drive the car also, although would need to be somewhere safe, or, have someone else drive it while I watch the live data.

 

[Ian Schmidt]

That's a good question. If there are instructions for flat towing it that should get the wheels spinning freely. Otherwise you could have someone else drive it and watch the live data, or vice-versa. Then assuming the data drops out you can try to figure out if it's related to steering (which is probably a wiring problem), or if it just drops out all the time it's likely the rotor.

Something else you could try is to swap the sensors left and right and see if the code follows the sensor. For sensors in particular it's not unknown for them to misbehave out of the box, especially if it's not an OEM part.

 

[mnalep]

So, I put in a new sensor cable on. Then drove the car, and the ABS (and other lights) turned off. Drove for about a week with no lights, then they came on again. Drove for about 20 minutes home with the ABS light on.

After getting home, I parked in my driveway and turned the car off/on about 5 times, then went for a drive and the ABS lights turned off in first 15 seconds of driving (this also happened right after putting in new sensor/cable last week).

But, this time when the ABS lights went off, and when I tapped the brakes, the ABS system activated and I felt the pedal pulse and heard the pads clicking! I was only going about 15 mph, and the pavement was dry, so this was not expected. I parked the car, and turned the car off/on a few times, and, then when I started moving the ABS lights came back on, but, the brakes worked normally again (no ABS activation upon braking).

It seemed like when the ABS lights went off - the ABS system activated, then, when the ABS lights came on - the ABS deactivated.

Then, the next morning I let Autozone check with their OBD2 scanner, and the C0205 was on again, so, I pulled the ABS sensor out, and cleaned off a very small amount of 'dust' that was on the magnetic sensor. I have now driven the car two days with no ABS lights on, and, no activation of the ABS braking.

I also checked my tire pressure, as I had the TPMS light on, and saw all four of my tires were at 35psi. The manual says they should be at 30psi - so I let some air out and tires are all now at 30psi. (I only mention this because I started to wonder if the over-inflated tires might have some affect on the ABS lights coming on? I know it sounds unlikely, but, these computer monitors could do that ... maybe?)

So far, the ABS light has been off for the last two days. Why would this ABS issue keep coming and going?

 

[HaloRomeo27]

What i have learned about replacing those components is you will need a very expensive tool to go in and re set abs learned values i spent 5,000 on my tool it does key programming but i want another version that does hybrids

 

[mnalep]

What i have learned about replacing those components is you will need a very expensive tool to go in and re set abs learned values i spent 5,000 on my tool it does key programming but i want another version that does hybrids

So, an update - it's now Feb 24, 2024, about 3 months since Input the new ABS cable in. The ABS light has not come back on, and I no longer have the C0205 code.

Thanks for your input. I did not know abs signals are stored. But, I cannot afford 5,000 - so I would just let the computer re-learn - if that is possible? Or I would keep l cleaning the sensor, or get a OEM sensor, if cleaning failed to help. What tool do you have? Perhaps there are cheaper versions now if you buught it a while ago?

 

[HaloRomeo27]

I have an Autel MaxiIM IM608 Pro i find it very nice for diag and live data and in my honest opinion always go OEM on parts yes there a little more expensive from what i have seen the aftermarket stuff tends to cause issues or does not fit correctly

 

[HaloRomeo27]

My diag tool is for mainly key programming and at some point i will get the other model that covers hybrids it is about 6,000
I can’t stress this enough take the time to find out what is causing the issue before throwing a parts cannon at it and if you can find a good tech that is willing to help you diag this correctly it will save you frustration and money