Vehicle is a 97 S Series 4X4.
According to the book it can have either the older sensor on backing
plate or the newer sensor in hub design. The problem is the book doesn't
say when the change occurred or if you can replace the older units with
the new design without problems. Anyone have the answer? Or a place to
get the answer? Put the scanner on it and don't see any problems but the
ABS is flakey, but it isn't turning on the light.
That's where the problem is. This rig has had most of the front parts
replaced. New hubs, brakes, backing plates, ball joints,linkage and
such. I'm assuming the integrals on it are correct BUT I found splices
in the sensor line on the right side. Made me wonder if the PO had
replaced the separate units with the newer parts.
Local HUUGGE dealer counterman didn't have a clue. I was asking him to
run the VIN but he said that wouldn't tell anything. Seems strange that
GM wouldn't tag when the change from first to second generation sensors
occurred (at least to me it's strange, but GM plays by there own rules)
The factory book just says that they changed the sensors in 97. Since I
normally just go by what is already there I never ran into this one
before. Maybe I need to beat on a different counterman!
Really don't want to have to buy all new hubs and backers just to get
the ABS to the point I can actually test it.
Steve-on that 97 most come with the sensor set up that is attached to
the brake plate-I don't believe I've ever saw any different on a 97
but....I guess it may be possible that it'll have the 98 and up style
that attaches with an allen bolt to the wheel bearing housing. I have
never changed out the former style and I do believe that right and
left are different(ck with your jobber) thus eliminating the ability
to switch left and right to pinpoint an problem. Now on the later(98
and up) I have changed them out with some(pretty good) success. The
problem you referred to in an earlier post about the brake pedal, etc.
may be caused by this spliced wire you've discovered. Does your scan
tool have the ability to look at each speed sensor and what speed they
are reporting at all times. I sort of think if you can see that-
you'll see that spliced side 'dropping' out-speedwise as you decrease
speed. Hope this helps you! In conclusion, from what I know, I
think(guess) a dust shield with included speed sensor from GM may
solve your issue-seen many of em. If all else is good-this may be all
you need but they aren't cheap...but what is. Good luck!jp
Well I had some spare time so I tore into the beast today and discovered
it has a mixed sensor set.... Now I know why the ABS is messed up! Left
side is original backer plate/sensor and tone ring, right side is
Since I have a good plate and hub I'll be changing those out.
Also had some free time with the test gear so I played with the sensors
on the 97 and the 94. Discovered that the only part that would hinder
the swap to the newer style integral sensors is the tone ring in the
transmission. The speed sensors are the same but they read different
speeds so the ring must be different. The speedometer could be corrected
easily but the ABS reads all three sensors so it would always think you
had a problem. Changing the ring would solve that but who wants to tear
out the transfer case just for that.
I believe the reason for that is that alot of GM mid year changes are
not done by VIN but by production date and packaged offered. if it is
a 97 why take it to the dealer any way, I work in a private shop and
have worked in a dealer and private shops are alot more afordable to
If you do have a scan tool check wheel speed sensor operation if all 3
or 4 sensors are good check the switch near the front diff. for the 4
wheel drive I can''t remember right now but I think that it was GM
that had a vaccum Issue with this sensor, this may be causing false
You can not swith witch style ABS sensor you are using though!
Any car manufacture though does what ever they want because they can!
The more they switch mid year the harder it is to manufacture
aftermarket parts because the aftermarket companies can not keep up!
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