2011 RDX
122k

I'm having an issue where my VSA system is activating while taking right turns. Like it thinks the car is sliding but it's not. Shortly afterwards the VSA system deactivates and the light turns on. If I continue driving the SH-AWD light turns on and disengages the rear diff. I recently had another issue with this vehicle. I had a misfire on cylinder 3. That was the first time the VSA light has come on. They fixed the misfire but the VSA light came back a few days later. It has been on since but it did not start causing these other issues until recently. I had my mechanic scan it and he did not find anything. He did lift it up and discovered that I needed new tie rods on the driverside and replaced them. The light still persisted. He scanned it again and found nothing (does not surprise me because the light does not turn on unless I drive a bit.) He lifted it up and checked the wiring of my speed sensors. They were fine. He also double checked the wheel bearings but they had no play. He changed the diffs. 10k ago with genuine Acura fluid. I did receive one message on the screen the first time the rear diff. was disengaged (All Wheel Drive-16) but it seems to be useless. I can't find it anywhere. The car has no issues taking left turns. Anybody have any input?

 

This has to be a problem with one of the wheel speed sensors or magnetic encoders in the wheel bearings. Because it's only occurring during right turns it would be an intermittent wiring problem with a wheel speed sensor or a change in gap between the wheel sensor and encoder due to bearing play or maybe dirt/debris in the wheel bearing encoder area. I think you'll need a scanner that can read the wheel speed sensors in real time while you're driving to determine which wheel has the problem. Does it matter how fast you're going when you're turning right when the problem occurs? Does it matter how sharp the right turn is when the problem occurs? I ask these questions because if it's a speed related problem I would say it's more bearing/encoder related and if it's sharpness of turn related I'd say it might be more wiring related.

 

It happens at speeds over 15mph and only on full right turns. I can turn the wheel slightly to the right. No issues. It almost stops the whole car. Could this by chance have anything to do with the Steering angle sensor as well? The steering wheel doesn't feel like it usually does. I did have to take this car to Acura at one point to have the Air/fuel Ratio sensor replaced. This sensor threw the vsa/sh-awd lights along with check emissions. Then right before I got there the SAS code showed up. Acura asked me if I noticed any unusual behavior while turning and I didn't so they re-learned it. Could the relearning lead to these issues without a code?

 

Also, could these magnets be bad without the bearing showing play? They are 13 years old with 122k. I understand the whole bearing would need replaced but we can't find play and he took it apart and cleaned it up. I understand you may not exactly know, but I appreciate the help.

 

I didn't know you had an SAS code, the relearn would be to set the steering in the center position. I'm surprised the dealer didn't read a code or pending code for the SAS problem? The steering position sensor is certainly a key input for the VSA system operation but I would really expect a code or codes if there's a problem with this sensor. Does it make any difference if the VSA switch is off?
Because of no codes it's like there's no hard failures detected with the wheel speed sensors or the other sensors but there is a VSA type correction event happening. There's a yaw rate lateral acceleration sensor and the steering angle sensor in addition to the wheel speed sensors. Maybe it is the steering angle sensor or possibly the yaw rate sensor instead of bad wheel speed input. I'd really like know if you have this same problem with the VSA switched off.

 

The problem does not occur when the VSA is off. Whether I turn it off myself or the car does. The car deactivates the VSA system itself after the issue occurs once or twice.

 

It also occurs at highway speeds when the car is going straight. Unless VSA is off.

 

Okay, since it is definitely a VSA related issue then there are a couple of things you can do yourself and then if this doesn't work a live stream of the VSA related sensors will be needed. First, you could try unplugging the big connector on the ABS pump module, unplug and plug back in several times to try and clean the pins and sockets in this connector. Or, unplug clean with electrical cleaner, blow dry and reconnect. If this doesn't help then could have the SAS center point relearn done again and I think there's also a calibration for the yaw sensor. If all this doesn't work then you'll have to get a look at the sensor inputs. I've attached a link to a Youtube video that I've watched before and is very helpful.

 

Most likely a wheel speed sensor like the others said. I had it go wrong on my volvo which required an ABS ring replacement. The cars usually do a self check on each start, and it will not identify an issue until you go over a certain speed, ie the check fails. I had a scanner that could view live data and you probably can just check the ABS sensors as others mentioned in live data.

I dont know how honda setup their diagnostics, but for Volvo it told me it was a mechanical failure (issue with the ring and not the sensor wires) and the side it was on. In my case it disabled ABS and led to erroneous ABS braking at low speeds until it was fixed.

Another cause may be that the wheel hub is loose, check to ensure the axel is torqued correctly to the hub and there is no play. Unfortunately as you said, it seems that the whole bearing would need to be replaced to rectify a failed magnetic encoder. A PITA!

Foxwell had a good NT510 elite scanner, but it required older honda software to work fully with these trucks. I can forward a copy later along with instructions on how to install. You could pick up one of their newer scanners and it should work fine as well. I would advise you buy one as each hour of diagnostic by Acura/Honda can be 120-180 cad depending on dealership. In most cases they just plug in a scanner and read, something you could do at home.

 

I bought a scanner before I posted this. CGSULIT SC530 scan tool. Its bidirectional. It is programmed for Honda and Acura. It scans all systems and it found a fault with the Steering angle sensor. "STEERING ANGLE SENSOR MALFUNCTION. STEERING ANGLE SENSOR NEUTRAL POSITION INCORRECT." This scanner can also calibrate the SAS. My next question, does this mean it needs a new sensor? Or just recalibration? Other question: is the recalibration what you need Acura for after you replace the sensor? I know you might not know exactly but if this is the case I may no longer need Acura for many things. It can recalibrate and relearn 26 different systems on the car.

 

The 134 error code showed up on the scanner but the car does not display it which might be due to them relearning it the last time I was there.

 

These detailed scanners will show numerous stored codes that will not show up on the cars display nor a normal obd2 scan. You can try to relearn the neutral position and see if it makes a difference.

Since my partner received her car we did the following:
Transmission position switch change
Serpentine belt
Power steering flush
Trans flush and relearn x2
Replaced starter
Idle Relearn
Alternator swap
Power steering pump swap.

We buy some parts from the dealership but with the scan tool we had no need to go to them.

For hondas i would say yea it is all you need, there is no can bus code logging or programming AFAIK.

 

My philosophy is to clear the code, do the relearn. if it comes back you got an issue, if it doesnt you are fine.

 

Cleared it, went to do the relearn it told me to turn the car off and then back on. Then it tells me it working on it, then it says process incomplete. I'm guessing that means it's bad and needs replaced. Tried it 3 times. Input?

 

Do you know if your scanner can read the steering angle sensor (steering wheel position) in real time? Is so I would try to get a look at the position readings when the steering wheel is straight ahead and turned left and right to a known amount. I've seen some scanners show the steering wheel position in degrees and you should see near 0 degree in the straight-ahead position.

 

It gives live data. I will check that out. I went on a drive after I tried to re-learn. The VSA light came back. I scanned it again and the "STEERING ANGLE SENSOR MALFUNCTION. STEERING ANGLE SENSOR NEUTRAL POSITION INCORRECT." Did not come back but the 134- Steering angle sensor malfunction did. I'm beginning to think the sensor is botched.

 

I'm thinking the sensor may be bad too, it should calibrate to the neutral position. This is why I wanted to see if you could get a reading at the straight ahead or neutral position, if it's way off this would help confirm the sensor is bad.

 

When the wheel is straight it shows a value of 23.375. Number decreases when I turn to the left.

 

I know you can set the steering angle center point using HDS and that would be worth a try....

 

I don't know what to tell you about this value, I just checked my car and it read 51.5 in the centered, straight-ahead position. This is not the value I expected so I did a calibration and saw the same value afterwards. As I turn the wheel to the left the value decreases. My car has no codes and no problems when driving and it's a FWD model. Not sure what's a good value and what isn't, I expected near 0 degrees when in the straight-ahead position.

 

I cleared the code again and reset the center point. It then showed 51.5. Test drove it and the issues are gone. Tested the abs/vsa system afterwards and there were no faults found! Thank you guys so much! This scanner was cheaper than the fee Acura charges just to look at your car and the closest dealer is 45 minutes away. Your help was awesome! Thank you so much!