OK fellas, certainly not a hard core rock crawlin' question...

If the ECU is able to detect an open circuit in the sensor circuit, there has to be a given degree of continuity through the sensor. Anybody know what this resistance should be on a good sensor?

Damned diagnostic tools only go so far and I do not wish to buy yet another piece of diagnostic equipment. Anybody got a Snap-On EETM 300 for cheap?

Peace,
PT

http://www.asashop.org/autoinc/aug2001/mech.cfm


Googgle " ABS variable reluctance " for more pages and info.

For what it's worth, on the DII's at least, you can now buy the ABS sensors alone, instead of having to purchase the entire hub assembly.

If the fault codes do indicate a sensor then read on...

Although the sensor is the thing that is sitting out
in the mud, I'm guessing that it is just an inductive
pickup and therefore not too unreliable.

Sometimes these sensors slip out a little, the induced
voltage is very dependent upon the airgap between the
toothed wheel and the sensor - I think the idea is to
push the sensor in until it makes contact, and the
toothed wheel will push it back to the right position.

My money would be on the connections and the cable
where it enters the sensor. So you may have to
move the cables around to find any intermittent
connections while you are performing the
measurements below.
(how many arms did you say you had?)

If you know one end of a multimeter from
another, you could try.....

firstly - measure the resistance, best done at the
ABS controller end - should be between 900
and 2000 ohms.

secondly -
1/ Jack up the diff in question,
2/ connect a multimeter across the sensor,
3/ spin the wheel at 1/2 revolution per second (30 rpm)
4/ measure the voltage, must be greater than 200mV peak
ac.

The ABS comes from wabco, There are a few tests
listed on the wabco web site specifically for the wheel
sensor....

BTW The sensors are truck ones available from truck suppliers with the WABCO part number from the existing sensor

If you know one end of a multi-meter, you could try... LOL.

First off, I have a Ham Radio license and a soldering iron-watch out fellas, this one might work! LOL If my dad were here, he'd be telling jokes about my oscilloscope "collection".

Secondly, I have already ohmed out the wiring from the wheel to the ECU, both open circuit and closed (jumpers at wheel end, AMP connector disengaged from ECU). I have sequentially connected each sensor and run Rovacom diagnostics after each step. I have used the graphing voltmeter on each sensor while turning the wheel.

It appears that the front two sensors are bad, in spite of the robust nature of their construction.

I'm off to visit my friend at the truck parts shop.

Thanx fellas.
PT

Paul
I cut and paste this from elsewhere
I 'm sure you know a multimeter plenty.
No disrespect intended :flipoff2: