Moderator: volvite
TooMuchControl wrote: ↑Wed Jul 27, 2022 4:24 pmis it anything like what this Nissan had a problem with?
Nissan Pathfinder: Traction Control Kicks On When Turning A Corner
https://www.youtube.com/watch?v=Hc8X7eE ... oRepairLLC
If not, then wheel sensor is my bet on this.
Scan tool hooked up while driving will determine which wheel is "slower/faster" than the others.
Would the ABS have codes stored even if the slip, brake and/or VSC lights never came on? Would you have a a reasonably priced recommendation for an ABS capable scanner?VStar650CL wrote: ↑Wed Jul 27, 2022 7:06 amThe ABS should have codes in it. Could be a wheel sensor, but could also be the Steering Angle Sensor (SAS), they're a frequent-failure item on R51's. If that is the issue, check prices on a whole combination switch instead of just the sensor. The price for those sensors alone is semi-insane and a whole switch assembly is usually cheaper. If you don't have an ABS-capable scanner, the ones at the parts stores are almost always ABS-capable.
If the SAS is "falsing" a few milliseconds at a time then there may not be any codes in it, because the ABS doesn't realize anything is wrong. That's actually pretty common when SAS's first begin to fail. Less commonly, a miscalibrated or failing G-sensor could cause similar issues with no ABS lights. On the other hand, Bosch ABS's are very picky about wheel sensors and usually a single missed-tooth on a reluctor will throw a code and turn on the ABS lamp. So anything is possible, but a wheel sensor would be at the bottom of my checklist.
Aftermarket sensors generally do fine. Make sure you check the wheel bearings and clear any magnetic trash off the reluctor before you summarily replace it. Things can be wrong that aren't the sensor's fault.
Gotcha, thanks for laying that out logically. Any advise on how to check for the SAS outside of taking it to a shop with a fancy scanner?VStar650CL wrote: ↑Thu Jul 28, 2022 5:35 amIf the SAS is "falsing" a few milliseconds at a time then there may not be any codes in it, because the ABS doesn't realize anything is wrong. That's actually pretty common when SAS's first begin to fail. Less commonly, a miscalibrated or failing G-sensor could cause similar issues with no ABS lights. On the other hand, Bosch ABS's are very picky about wheel sensors and usually a single missed-tooth on a reluctor will throw a code and turn on the ABS lamp. So anything is possible, but a wheel sensor would be at the bottom of my checklist.
You're most welcome. With a falsing SAS, sometimes even a scanner won't catch it. I had a Juke some years back that every couple of miles would tap the right rear actuator for no apparent reason. Just one tap, then it was fine again. Graphing the wheel sensors and SAS told us nothing, The only way we caught it was to put the C3+ in log mode and trigger it on the actuator signal with a 20% pre-trigger applied, then expanded the output with Flying Graph, which has finer resolution than the C3+ graph. We saw a single glitched reading with a duration under 10 milliseconds, but that was enough to make the ABS react. However, as I mentioned earlier, the Bosch 7S000 sensors on the R51 (as well as Titans/Xterras/Frontiers) do fail. I wouldn't call it an "everyday" failure rate, but frequent enough to call it a "known issue". The ABS looks at the G-sensor in a more leisurely manner unless the steering and wheels indicate possible yaw, so you can eliminate that for sure just by scanning and exercising it like the guy in the vid. If that checks out and there are no wheel codes, you can be pretty certain your SAS is glitchy.brickbox wrote: ↑Thu Jul 28, 2022 8:21 amGotcha, thanks for laying that out logically. Any advise on how to check for the SAS outside of taking it to a shop with a fancy scanner?
I’ve had a failing ABS wheel speed sensor on a previous vehicle, but that one would only occur when I was at really low speeds (like 20mph or so). This one has me baffled.
It's probably fine to drive it as long as the glitching isn't causing uncontrollability issues. Pulling the fuse is fine provided it doesn't make the engine or tranny go limp. It might, that behavior varies from model to model.
So I ended up purchasing Bluedriver and it shows no ABS codes. The local advance auto didn’t have a code reader capable of reading ABS….VStar650CL wrote: ↑Thu Jul 28, 2022 8:44 amYou're most welcome. With a falsing SAS, sometimes even a scanner won't catch it. I had a Juke some years back that every couple of miles would tap the right rear actuator for no apparent reason. Just one tap, then it was fine again. Graphing the wheel sensors and SAS told us nothing, The only way we caught it was to put the C3+ in log mode and trigger it on the actuator signal with a 20% pre-trigger applied, then expanded the output with Flying Graph, which has finer resolution than the C3+ graph. We saw a single glitched reading with a duration under 10 milliseconds, but that was enough to make the ABS react. However, as I mentioned earlier, the Bosch 7S000 sensors on the R51 (as well as Titans/Xterras/Frontiers) do fail. I wouldn't call it an "everyday" failure rate, but frequent enough to call it a "known issue". The ABS looks at the G-sensor in a more leisurely manner unless the steering and wheels indicate possible yaw, so you can eliminate that for sure just by scanning and exercising it like the guy in the vid. If that checks out and there are no wheel codes, you can be pretty certain your SAS is glitchy.brickbox wrote: ↑Thu Jul 28, 2022 8:21 amGotcha, thanks for laying that out logically. Any advise on how to check for the SAS outside of taking it to a shop with a fancy scanner?
I’ve had a failing ABS wheel speed sensor on a previous vehicle, but that one would only occur when I was at really low speeds (like 20mph or so). This one has me baffled.
It's probably fine to drive it as long as the glitching isn't causing uncontrollability issues. Pulling the fuse is fine provided it doesn't make the engine or tranny go limp. It might, that behavior varies from model to model.
That is a good point. I went and looked at the tires as they came with the Pathy when I bought it a couple years ago. They are all the same, 265/65/17.ShipFixer wrote: ↑Sat Jul 30, 2022 11:56 amThis is probably not your cause, but...I once had this issue because Sears installed one slightly smaller tire in a new set of four. Didn't notice for a couple months until ABS noticed the speed difference between the two rear wheels downhill coming out of the mountains at highway speeds and started freaking out. I assumed it was a brake issue until I looked really closely at the tires.