Max Blast

Yup, 2 for 2 on the 2 cars I’ve had.

Search other threads for other users like kind experiences.

It’s like replacing only one weak valve in a plumbing system - by introducing a new strong point in the system very shortly the water pressure will create a leak on the remaining weak valves, and you’ll have a new leak. This occurs on the paired wheel speed sensors connected to one axle via shared or interconnected harness. Battery voltage quickly burns out the older weaker sensor because it is now the weak point in the system.

this is also how airmatic works, or should I say; fails.

N_Jay

I Bet the same is true of headlights. When one burns out thr other will likely go soon due to the extra energy it gets.
Your understanding of electroelectronics is incredible.
You should teach an EE course.

I mean it is not as if similar parts from the same manufacturinh lot have no reason to fail in about the same amount of time when used in the same environment.
THAT would just be "Crazy Talk"!

Max Blast

Cool. Your application of sarcasm here indicates you disrespectfully disagree, so go get some data to support your position.

This is a well documented failure mode on the x164 and on similar MB of this architecture. Wheel speed sensors fail in pairs.

N_Jay

If you say so. (As do many parts exposed to the same conditions.)

seacoaster

I had the ABS ESP come on, Snap on scan tool said right front unreadable(can't remember the exact language) I replaced the front speed sensor and still have the ABS ESP light, still say right front. My mechanic reset the car, lights were off for 3 minutes then came back on. Re read it, same thing, right front. Any thoughts on this issue other than replacing the speed sensor. I notice when I drive away, the drivers front will make a quick ABS sound the roll normal. The car has done a number of things since the initial lights came on, shifts up to 4th(resets after a shutdown), seems like it is in a slow mode(not limp) as well the lights have shut off for a drive here and there). I think the transmission stuff is due to the wheel speed being unknown. Codes are 5399, 5112,0721

Max Blast

You needed to replace both sensors on the front axle. If that is where the initial fault was.

seacoaster

Yes, right front and I only replaced the one. Just confirming, if the system still only reads right front after replacing the right front I need to change the left as well. Any explanation, or is it just that simple?

seacoaster

Also, will they automatically reset or will I have to clear with the scan tool?

Max Blast

Once a valid input is seen from a previously invalid sensor, the ESP/ABS fault should auto clear. Only if there continues to be an invalid input from one or more sensor(s) will you continue to have the symptoms that you are describing that you still have.

Of course there could also be an internal faults with your ABS box that would be independent of a sensor but nine out of 10 times the sensor triggers this fault.

seacoaster

Thank you @ Max Blast, pulled it back off today and cleaned the interior, lots of gunk, but still getting faults. I will try changing the other sensor as you recommended

N_Jay

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If the sensor is unreadable, it could be wiring or a connector.

Max Blast

Specifically where the harness is held on the axle and also where it passes
through the wheel well liner.