What is the behaviour of the ABS module when ABS light is on

[chefwong]

I have not brought it back to the shop, but we suspect I may have a failing ABS module. ABS light came on, swapped the offending sensor per GT1 diags and the light still comes on ...and stays on when it get's triggered.

OT, but rolling down a very short pitch/flat at 5-8 mph, and slightly triggering the brakes, there was some pulsation I noticed when throttling on the brake. Could be ABS feedback coming through the pedal or something else...but definitely some funky pulsation occurred.

I need to make time to get back to the shop but just out of curiousity, what other weird behaviors should be noticed or ill effect when you either have a bad speed sensor or just the module going bad

[Weasel]

Which sensor is the fault for? (which corner)

[chefwong]

RR

[chefwong]

BTW, came across your past responses on abs threads wesal. For the past couple of days, it not prior to sensor sway (just last week), there has never been a DSC light...

It varies but after a bit of driving, depending if I hit the freeway or locals.....I get it to trigger the ABS light and then it stays on till I turn the car off.

[Weasel]

Right rear, likely is the DSC module. If it were the left rear it could possibly be the instrument cluster as it shares the signal... but right rear is usually the DSC module.

I had this same thing on my X before, sometimes the light would come on, some times it wouldn't. Then it kept getting more and more frequent/consistent till I had the time to change the module. 2 years later no more problems.

[chefwong]

you would suspect the DSC module even though there has never ever been DSC light on the cluster.

Just short of assuming it's a bad module, if when we plug the GT1 and it still tell's me it's a bad sensor on the same wheel on which a brand new one was replaced, I would assume the next fault in line would be the ABS module and not the DSC. Thoughts, suggestions ?

[Negritoamni]

If GT1 is telling you the the sensor signal is "plausilble" . Before spending any money, hook up your GT1 and find a parking lot for a road test, w/ a second person to keep eyes on scanner...view diag request under DSC and select all ABS sensors to display. Fell free to do u-turns, eights and drive straight, but keep it under 20km ( it will not read above 20km) you will find the sensor that is failing reading 0km with the vehicle in motion.
Happened to me...Right rear sensor
Also do a continuity test from the DSC connector to check all Sensors, before replacing any parts.(remove Driver side headlight for access to DSC connector, you will have full access to this connector),
Good luck

[Weasel]

I would definitely spend a few bucks on proper diagnosis by dealer before shelling out the big bucks for a DSC module. (by the way, ABS and DSC are the same module)

But if you have your own GT1 you can do more diagnosis yourself. As mentioned above, look at the wheel speed sensors in diagnostic request through control module functions and you will see if it is reading. You can also look up the wiring schematics in the GT1 and ohmically check the wiring from the sensor to the module if need be.

But if the sensor isn't the problem it will likely be the module as the circuit/chipset that reads the signal inside the module is likely what is going out. And the module will need to be encoded after replacement along with some initializations like steering angle reset etc.

[chefwong]

Gotcha.
Actually, P&L is covered for the most part.
Warranty Direct has been very good to me....

Just short of $100 ded, they have covered 85% of my issues with no bickering ....
As a matter of fact, my INDY was so impressed with their seamless transaction, he told me he recommended them to another customer who's aftermarket warranty denied 90% of the repair labor.

I'm keeping her for just a couple more months. Warranty expires in Dec so it's good that the last remaining $$ repairs are creeping up now. When it rains, it pour. SES came on and per code, it looks like 02 sensor just today.

We'll see how WD plays out the ABS module.

The largest repair was in the tune of 3K - valley pan, alternator, and a bunch of odds ends and they approved it over the phone.

When I had some *suspension issues*, they did send a adjuster out but when all said and done, it was approved as well.

[chefwong]

Just a thumbs up for Warranty Direct.
Another painless transaction and module replacement approved.

BTW, big shout out and thanks to Weasel for this tech contributions to the board in general