Sweet. This will save many people a lot of time!! thanks for the write up

 

Awesome write up, thanks

Sent from AutoGuide.com App

 

anyway to test the module itself?

 

awsome wright up. Need to do this tonight to figure out a problem that came out yesterday while wheeling.

anybody have any coments on the replacement sensors that Rock auto sells???

 

not sure if I am doing this right found what pin to wires were and didn't get any response from my multy meter. tested a 10 amp fuse and got 001 ohms of resistance with that. not sure if the problem lies with the person holding the probes or with the truck

 

I don't know if theres a way to test the module itself without having it plugged into a consult computer at the dealer. Im sure you could bench test the pump similar to a starter motor to see if its working but the module im not sure.

Rock auto sensors are good one of my rear sensors I bought from them. Its working good so far.

Is the meter zeroing out when you touch the tips together. I was having trouble at first when I was testing the wires but I found that the pins are exposed on the side of the plug as well and found it a little easier to test.

 

ya the meter zeros out when I tough the probe tips together. had a guy that has a MAC OBD2 with ABS reader. didn't pull any codes but my tuner pulled 6. checked all of the fuses ( just to be sure) now looking for where I put my external hard drive that I saved the FSM on

 

ya the meter zeros out when I tough the probe tips together. had a guy that has a MAC OBD2 with ABS reader. didn't pull any codes but my tuner pulled 6. checked all of the fuses ( just to be sure) now looking for where I put my external hard drive that I saved the FSM on

Did you ever figure out why you were reading nothing when you pulled the abs connector? I have the same thing and I'm struggling to figure it out.

 

Is there a way to test a sensor if it is off the truck? I know which sensor that is giving a bad reading, but I want to know if the wiring is bad above the connection.

 

I checked this too when diagnosing. Took two small pieces of wire and stuck them into the plug (20 or 22 ga iirc). Put a volt meter on those with the truck running. If you get voltage, it's not the wiring. I believe it was 12v but I can't remember for sure.


Sent from AutoGuide.com Free App

 

Yep it should be somewhere in the 12v range. If it is anywhere below 11v then you may have a problem in the wires somewhere. I had a partial break in 1 of my abs wires and I was getting between 8-10v

 

Used this technique couple weeks ago and it worked perfectly on my 2005.

My readings were way higher than OP's but same concept applied look for anything odd across the four sets of wires:

Driver Front: 14 M Ohms
Pass Front: Open no resistance
Pass Rear: 15.84 M Ohms
Driver Rear: 8.09 M Ohms

I went to my pass front sensor and the previous owner had done a hack job repair on the wires and they had corroded away.

Thanks Primer!

 

THANK YOU. We needed this write up. Had the ABS/SLIP lights about 2 weeks ago. Had it to the dealer to see whats up. Bad rear ABS WHEEL SENSOR. NOT A CHEAP FIX! The rears are expensive. RA Lists them for $219/each.

 

I read all four just now on my 2005.
I'm reading 3-4M ohms.
Changed the battery in the meter and there's no change.
Anyone confirm this on a 2005?

 

These are active sensors, not passive. So the simple resistance test isn't as accurate. I've found that reversing the polarity on the two wires changes the results when doing a resistance test with a meter. Simply put a resistance test isn't a definitive test on these sensors. It is an aid, often pointing toward where to look.

If you want to test them correctly you need an active wheel speed sensor tester, one of those specialty tools.

So if you get odd results, it may not be a bad sensor or bad wiring. It might just be the way you are probing the sensor.

 

Hi guys...I got a question regarding the abs plug. Once I have removed the cover if the plug, I am unable to remove the plug from the module. No matter how much I wiggle around on it. And I can't see any lock on it. Really so frustrating, please help

 

Hi guys... I got a question regarding the ABS Plug. Once I have removed the Cover if the Plug, I am unable to remove the Plug from the Module. No matter how much I wiggle around on it. I can't see any Lock on it. Really so frustrating, please help

Pull up on this Lever, pull the Plug off, then pull the Cover off. There is a small Tab holding the Lever in place, you have to push that in to release the Lever;

This is the Plug you're looking for;

Then take the Cover off the Plug so you can see which Wires are which. Should be pretty self explanatory after reading the OP.

 

All (8) Photos placed into PB's Purgatory, have been Resurrected for this Thread! :thumbup:

 

Here is a little tip i stumbled upon while trying to diagnos my nissan frontier after reading this one. Think it will add some light to the active and passive sensors and help money stay in our pockets.

Testing an Active Speed Sensor

The best tool for testing the active speed sensor is a good scanner, preferably one that can show the separate speed sensors in graph form. A lab scope is probably the best for a more precise answer and can be attached directly at the sensor to read the individual sensors or wires rather than the entire system as with the scanner. But if you’re looking for a quick test to determine if just the speed sensor is in working order you can make a quick little tester yourself.

LED Tester

You'll need a 220 ohm resistor, an LED and a 12v battery source. Disconnect the sensor from the car, (DO NOT TRY THIS WITH IT HOOKED UP!) hook up the battery to one side of the sensor leads, the other lead from the sensor is hooked up to your resistor and LED, the remaining lead from your LED should return to the battery. An LED is polarity conscious, be sure to have the current flowing in the right direction or it won’t light up at all. (The sensor doesn’t care which direction just the LED does). What you’ll see as you spin the wheel is your LED blinking on and off with an increasing and decreasing blink as the wheel speed changes.

This is one of those times when the old school test light isn’t going to help you out at all; in fact, it might create more of a problem. Your scope or your scanner on these types of sensors is the better choice. But, this quick little LED tester might help you with your diagnostics; it won’t test the entire system but will confirm if the speed sensor is functioning. Testing is always better when you have more than one method to determine the condition of a component. In this case, a scanner, a scope, or a homemade LED tester can help you in diagnosing these active speed sensors.

Always test first, test second… and when still in doubt… test a third time.

 

This by far is an amazing write up for a situation where it is a guess as to what sensor is bad, especially if you are unable to get a code! These WSS' are anything but cheap $$, so this is a great troubleshooting guide to drill down the issue. Thumbs up to @Primer

 

Thanks man!! I know not the coolest write up but hey if it helps someone I’m happy. Yeah those sensors are ridiculously priced, especially the rears for $200 a piece last time I checked.

 

Thank you

Wonderful, helpful post. Thank you!
I just wanted to do a slight update on the colors. My Titan 2004 was slightly different on the colors but this post pointed me in the correct direction and was able to fix my issue at no cost.

Driver Front- Brown/white & Green/brown
Driver Rear - Pink & Blue
Pass Front - Black/Red & Brown
Pass Rear - Purple/White & Green/Yellow

Wires between the ABS sensor and wiring harness had melted due to a bad exhaust back near the passenger rear sensor and just eventually broke one of the 2 wires going to the ABS sensor. I had to eliminate the connectors but worked just fine. Had to drive it a short distance to have the lights go off but after that no issues. 4x4 engaged no problem.

Highly recommend this method for testing and locating the correct sensor. After getting 3 positive responses when testing with the multimeter I knew right where to look and sure enough saw the broken/melted wire. Probably would not have seen it upon a simple visual inspection. Looked fine until I got right in there and started pulling back the shielding.

 

So I followed the procedure but I got no resistance (open circuit) value from all 4 sensors. Could this indicated something else is wrong? My multimeter was working but I could not get a single measurement from any of the combinations posted here. Anyone have any ideas?

 

flip flop your leads. they are directional. it will be open if you have them backwards.

 

If I go in and unplug the ABS sensor from the wheel side can I check that with a multimeter? Should I expect to see resistance in the same ranges? Much more of a PITA to go around and unplug them all just to check but I dont know how else to go about it

 

Yep


..

 

Can anyone confirm the resistance values I should be seeing? OP said 800-1400 OHMS but them commenters are saying they are seeing 8-14 M ohms (8000000 - 14000000 Ohms)

My Multimeter only goes up to 2000K Ohms (Like this)

Can anyone that has done this test confirm what readings youre getting?

 

Great write up

I have a 2005 Frontier SE (6spd, 4x4) and came across this helpful article.
First wanted to say thanks to everyone contributing and because its still relatively active, I thought I'd share my experience

I bought the truck on Craigslist and the ABS & SLIP lights came on just once in a while. I checked out the sensors and found a very poor DIY job from someone previous on the passenger front wheel: Wire nuts, electrical tape, bypassed the connector with some jumper wires. Yuck. I figured I would re-do it right.

I replaced the sensor with a $16 sensor on amazon instead of the $55 part from NAPA.

Now the light is on ALL the time instead of just intermittently. 4x4 will not engage and neither will cruise control; I reckon because the car thinks its slipping.

Then I found this article. Awesome.

3 of my 4 abs sensors are reading around 34.5 Mohms (I think my number is so different because it is a 6 spd. The sensors are different depending on the transmission)
The one I replaced is reading .465 Mohms... I figure I will try to return it because it doesnt meet spec. Now I will be looking at Rock auto or NAPA for the real part.

 

Just thought I'd add here what my readings were in case it helps anyone who is also troubleshooting their ABS sensors. These active sensors are difficult to test because their impedance varies depending on the input voltage. However, I was able to successfully test with my multimeter in resistance mode. I found 3 sensors with 18-19 MOhm resistances and the remaining sensor with a 1.4 kOhm resistance. As specified, if my lead polarity was incorrect I saw open circuit for all sensors. Replaced the outlier and everything worked.

 

I am now having issues with the 3 warning lights in question. 2007, 2wd SE, 225,000 miles. Lights came on yesterday. I checked all fuses and are all ok. Battery cables tight, gas cap tight, grounds tight. Truck starts and runs fine. I disconnected both battery cables and held them together for about a minute then reconnected. Started truck and lights still on. Left the house and by the time I was leaving neighborhood the lights went off. Last night we left the house and lights came on again. Drove bout 100 miles and still on, truck runs fine. Trying to test resistance at the ABS module plug but only getting any kind of reading at the driver front, red/dark green wires. Only seeing about 190ohm. Not getting any reading at any other pair of wires. I have seen here where this isn't best way to test but starting with this. Any thoughts?