RABS diagnostic connector

[jem270]

I just want to make sure this is the right test connector. The EVTM manual says the test connector is the C380 which is under the hood drivers side near master cylinder. The factory service manual says it is next to the brake pedal which this is a picture of and is C111. The Chilton manual says something about seperating the two halves. Mine just looks like this.

Is this the right connector? It has the one wire that is black/orange.

[jem270]

Yep that is the connector. I turned the ignition switch to run (without starting) and waited until the anti lock light remained lit. Then I hooked a clip onto the connector and touched the emergency brake bracket and when I removed the clip the antilock light started blinking. It blinked 9 times and kept repeating itself. When I turned the ignition off it stopped blinking.

Here is the page from the factory manual. I hooked my tester (set to 20k) and it showed 1.

When I touched the two connectors together it showed 0.

When I touched the two connectors to the anti lock sensor it still showed 1.

I assume this means the anti lock sensor is bad.

Is that a correct assumption?

Does 1.0 mean resistance is greater than 2500 ohms?

[Steve83]

Originally Posted by jem270

I hooked my tester (set to 20k) and it showed 1.

Hooked the tester to WHAT? Did it show "1_______", or did it show "______1.0"?

Originally Posted by jem270

When I touched the two connectors together it showed 0.

WHICH 2 connectors?

Originally Posted by jem270

When I touched the two connectors to the anti lock sensor it still showed 1.

WHICH 2 connectors? Did it show "1_______", or did it show "______1.0"?


1_______ means it's over the limit of whatever range you have it set to, e.g., if you have it set to the 20KOhm range, and it shows "1_______", the resistance between the test probes is greater than 20KOhm. If it shows "______1.0" in the 20KOhm range, that's a reading of 1.0KOhm .

[Need4racin]

hmm so you have to test it on 20k?

what is the code for 9 flashes?

[jem270]

Originally Posted by Steve83

Hooked the tester to WHAT? Did it show "1_______", or did it show "______1.0"?.

When I first turned the ohm meter on it showed 1._____

Originally Posted by Steve83

WHICH 2 connectors?.

I hooked the two ends of the ohm meter together. (Just to see if the ohm meter was working)

Originally Posted by Steve83

WHICH 2 connectors? Did it show "1_______", or did it show "______1.0"?.

When I touched the wires on the ohm meter to the ends of the RABS sensor connector ends the reading stayed at 1._____

Originally Posted by Steve83

1_______ means it's over the limit of whatever range you have it set to, e.g., if you have it set to the 20KOhm range, and it shows "1_______", the resistance between the test probes is greater than 20KOhm. If it shows "______1.0" in the 20KOhm range, that's a reading of 1.0KOhm .

So does a 1.______ reading at the 20k scale indicate that the RABS sensor is bad?

I know little to nothing about reading resistance in wires. I assume that the 1._____ reading is infinity or at least outside of the range selected on the ohm meter.

I also assume when you indicate 1._____ you are talking about the initial reading of the ohm meter (when it is not hooked to anything) which on mine shows 1. with nothing after it.

[jem270]

I guess I'll just buy another RABS speed sensor for the rear differential.

Does anyone have an opinion on any certain brand to get?

RAYBESTOS Part # ABS530000

BENDIX Part # Part No.40001

[Steve83]

Originally Posted by jem270

...the two ends of the ohm meter...

Those are the "probes". The "connectors" are on the truck wiring harness, or the part being tested.

Originally Posted by jem270

When I touched the wires on the ohm meter to the ends of the RABS sensor connector ends the reading stayed at 1._____ So does a 1.______ reading at the 20k scale indicate that the RABS sensor is bad?

Yes. It's called an "open circuit" failure.

Originally Posted by jem270

I assume that the 1._____ reading is ...outside of the range selected on the ohm meter.

Yes. Resistance is never actually infinite - it just gets so high (out of range) that it doesn't matter any more.

Originally Posted by jem270

I also assume when you indicate 1._____ you are talking about the initial reading of the ohm meter (when it is not hooked to anything) which on mine shows 1. with nothing after it.

Yes, that's my way of conveying a "1" at the far L of the display, but no, it's not limited to just when you turn the meter on. It applies at any time. The meter is always displaying what's between the probes, even when you set it down.

[jem270]

I bought a GP Sorensen part number ALS177 for $30.00. I tested it and my ohm meter showed 1.95 at the 20K scale. I plugged it in the differential and it appears to work. No more amber ABS light glowing on the dash!

Thanks everyone.