Mismatched ABS Sensor Question

[lostinthe202]

'99 Forester

 

I replaced the passenger's steering knuckle with a JY unit with one from a '95 Legacy.  The knuckle fit fine in every respect except that the camber bolt was problematic (posted in a different thread) and the ABS sensor from my Forester is too big in diameter to fit into the bore on the Legacy knuckle. 

 

At first I thought I was fortunate in that I clipped the wire for the Legacy sensor (I know, bad JY form I try not to clip wires when I don't need to, but I was in a time crunch) and so the sensor was still on the knuckle, so I just soldered it into the wiring.

 

I took my test drive, everything went fine, but I got to thinking that I don't really know how those sensors come into play in the system.  I understand that they are basically a magnet that sends a pulse every time the wheel goes around so that the ABS knows that the wheel is still turning and that if that one stops then the manifold eases the brake pressure to that sensor.

 

My question is, say my solder joint goes bad, gets ripped, gets torn etc and the connection fails.  What happens?  Is it just that the light will come on?  Further, the two sensors have different part numbers, does this mean that they have different resistance/magnet/electrical values of some sort that would damage the computer?

 

Probably overreacting, but I was just curious.

 

Thanks!

 

Will-

[idosubaru]

if there are any ABS faults the system simply sets the ABS light and results to normal braking, it is as if the ABS isn't there, brakes work as normal.

 

as long as the tooth counts on the tone ring are the same you're golden.  sounds like they are given you got no ABS light.

 

i would have tried to sleeve/space the original sensor in the larger space but if you got no check engine light then awesome, that was the easier solution.

[lostinthe202]

Gary,

 

Thanks for the info on how the ABS works, that's comforting.  As for the sensor, you've got it backwards, the Forester sensor is larger in diameter than the Legacy knuckle would allow, so I spliced in the Legacy sensor.  If it were the other way around I would definitely have shimmed it to fit.  Though I would have needed a longer bolt as the flange on the Forester sensor was about 2mm thicker than the Legacy sensor. 

[idosubaru]

couldn't drill out the ABS hole bigger for the forester sensor to slide in place?

 

it works without any ABS light right? that's awesome and that's all that matters, it's seeing the info it needs and it's all within spec if so.

[idosubaru]

and sorry if i steered you wrong on improper parts interchange, but glad it's hopefully working out.