4 whl ABS vs. 2 whl-How do I tell?

[DEZLPWR]

I just bought my '99 QC from a non-Dodge dealer and they don't know whether it has 4 whl ABS, 2 whl ABS, or none at all. I need to know what I have because the Abbott recalibration module won't work on 4 whl ABS but it will with 2 whl ABS. I'd rather not have to take it in to the Dodge dealer just to find this out. Is there an easy way to tell just by looking at the vehicle?

 

[MCummings]

Well, there would be a few places to look on it,, probably underneath the hood, there should be a little paper or something listing out the main details of the truck, (Engine, Transmission Axle Ratio, Paint, and ABS)



Well, My truck has 2wh (Rear-wheel) ABS on it,, and if you go out to a wide empty road, go along with some nice speed (about 45MPH or more) and Push the Brake pedal (and clutch) to the floor,, as hard as you can,, my truck will instantly lock the front wheels. but the rear-wheels will keep turning.



In a 4wheel ABS truck,, none of the tires should lock up.



That's the "Funner" way to find out, but also more expensive than just trying to find out by reading around... .





For fun,

MerrickNJr

 

[Deezul1]

Check for wires going to the front brake area on both wheels, that would mean 4 wheel ALB, I believe they all have at least RWAL, there is a bunch of wires going to the master cylinder on my 97 with 2wheel ALB.

 

[MikeR]

Easiest way is looking at the ABS module that's just behind the underhood fuse box toward the corner of the engine compartment. With 2wh ABS there will be one line going in and on going out of the piston assembly. 4wh ABS will have two lines in and two out,and also have two identical piston assemblies.



-Mike

 

[fest3er]

Originally posted by SCooke

... I need to know what I have because the Abbott recalibration module won't work on 4 whl ABS but it will with 2 whl ABS.

You should see wires coming from the front wheel sensors if it has 4WAL.



Also, the Abbott box can be modified to work with 4WAL; it requires the addition of a pull-up resistor on the input. The mod allows the Abbott box to correct the CAB-to-PCM signal. See http://user.mc.net/~murphyn/abbott-mod.pdf for the details.



Fest3er