Dodge ABS question

[Iron Horse Racing]

2007 Dodge 3500 DRW 6.7L diesel

So my ABS light came on about 2 months ago, as the speedo was still working, I left it....
Then the front u-joints started to to make noise, so I pulled the wheels, brakes, hubs and axles out and replaced the u-joints...
Well it's all apart I thought I'd fix the ABS....so which one is it,
No codes....
Fuses all look good...
No visual signs on the sensor wires
Break out the multi meter switch to ohms and the front left is open circuuit
Maybe I should check the front right, ok open circuit....????
Then I checked both for AC voltage, NOTHING....


OK what am I missing, what are the odds that both front wheel sensors died at the same time.....

 

[sirkdev]

Could it be a rear abs sensor?

 

[Iron Horse Racing]

Could it be a rear abs sensor?

Thought of that, "was told" if the speedo was working the rear sensor is fine????

Might have to double check it....

 

[Iron Horse Racing]

Spoke with another guy who said with the multi meter set on ac volts run a piece of metal back and forth by the sensor see I get a reading...

right one strong reading

Left one had to tap the sensor with the metal....

Is it possible the magnet just got to weak????

 

[the_real_wild1]

Sensors do fail. A better test would be to test for ac voltage with the tire on and spinning. The faster the tire spins the higher the voltage. I don't believe in the metal back and forth deal as it isn't very accurate. You can also check for dc voltage coming from the module to the sensor. Should have voltage going there. I know the big trucks have a 5 volts reference to them and think maybe automotive have the same???

 

[mountianguy]

The sensors should not read open. Its just a wire wrapped around a magnet. Try to cycle the ignition key for a code, it may be more specific. Did you try an external code reader this may also help.

 

[Iron Horse Racing]

The sensors should not read open. Its just a wire wrapped around a magnet. Try to cycle the ignition key for a code, it may be more specific. Did you try an external code reader this may also help.

I have a code reader, no codes.....

 

[Summitric]

Some smaller generic code readers may not pick-up abs codes....

 

[tex78]

I have a code reader, no codes.....

Code reader is only for ecm codes, abs is different module, you need a scanner to check abs codes

 

[Iron Horse Racing]

Code reader is only for ecm codes, abs is different module, you need a scanner to check abs codes

That's what I was thinking....

Some smaller generic code readers may not pick-up abs codes....

I have a generic code reader and the reader in the in the Smarty programmer, neither one displayed any codes...​

 

[Iron Horse Racing]

Thanks again for the advice.....

Turns out my original test, testing resistence (ohms) was correct, both front sensors were no longer reading.....

At the advice of my son......we picked up both new senosors and tested them both reading 495 ohms..

Between changing the front u-joints and these pesking senors, that seemed like a big job....

All done....no squeaking and no abs light .....

Miller time

 

[Ronaha]

When the ABS light comes on in the Chevy it usually means front bearing is pooched again lol