Sport Trac ABS theories & myths

[cncman]

Hi All,

I have an '02 sport trac 4WD and I am experiencing the same ABS malfunctions that many explorer owners have posted about here on the forums. I was on a national auto parts dealer's website tonight looking up ABS sensors for my sport trac and in the description of the front sensor I found this:

• ABS (Anti-lock braking system) wheel speed sensor sends a signal to the ABS controller reporting wheel speed
• When not replaced, anti-lock brake system may over-activate or override converting to conventional brakes, illuminate ABS light, and/or cause inaccurate transmission shift points

and this for the rear:

• When not replaced, vehicle may experience CEL/MIL illumination, high fuel consumption, loss of power and/or inaccurate transmission shift points

For some reason I don't buy these claims, but I have to say, however, that since my ABS started acting up:

• My newly replaced transmission is shifting hard and erratically
• My fuel economy is noticeably down
• and I kinda feel like I've got half a load of bricks in the bed when I put my foot down on the pedal

I was wondering if there was anything to these claims or if I'm just being a automotive hypochondriac. Regardless, I'm going to fix the ABS system anyway. Just looking for an intelligent (lol) discussion.

 

[brianwsnc]

You said:

"Just looking for an intelligent (lol) discussion. "


kind of a weird way to put things if you really want people to have a conversation with you. good luck with that. I don't qualify

 

[LONO100]

from dealing with a similar problem, i did a ton of reading myself on the subject and your abs sensor is also your speedo sensor, so yes, if your abs sensor is broken, your abs will not work and your speedo wont either. this will cause your tranny to act up. just make sure that its the abs sensor thats broken and not a fuse or something else causing the problems you are having. hope this helps.

 

[OffTrac]

I'm not an expert in this matter by any means but if the problems listed are exactly what you're experiencing, the culprit listed is told to be the reason and the solution, and your truck is telling you that it is the culprit...maybe it's more than a theory.

Maybe more experienced folks will have more insight. Seems like Lono has already dealt with the same thing. I don't really have a more intelligent answer than that.

 

[cncman]

I thought the speed sensor was in the transmission. My spedo works fine.

I understand that the engine has its controls and the transmission has its controls and the ABS has its own controls and they all work together, but the brake system affecting power and fuel consumption? That's what I find hard to believe.

 

[LONO100]

if your tranny is the one that uses the little plastic tooth gears, than yes you tranny dtermines your speed. if you have that little sensor that is on the top of your diff, then that is your abs sensor and it is also your speedo sensor. if it is broken, than your abs light will be on, and your speedo will be off too. this thread might help.

http://www.explorerforum.com/forums/showthread.php?t=329092

 

[tobeybj]

The rear wheel ABS sensor is integral to the electronic controls shifting the transmission properly. Driving in the wrong gear will adversely impact fuel mileage. Therefore, a faulty sensor can result in poor fuel mileage.

Plus, good rule of thumb...if it's broken, fix it. The danger of neglect is further damage.

 

[cncman]

I replaced the rear sensor last night since it was the easiest and cheapest, but that wasn't the problem.

The rear wheel ABS sensor is integral to the electronic controls shifting the transmission properly. Driving in the wrong gear will adversely impact fuel mileage. Therefore, a faulty sensor can result in poor fuel mileage.

I definitely understand that a bad speed sensor will cause these problems. I just thought for sure the speed sensor was in the transmission and independent of the ABS. Thanks for setting me straight.

I found front ABS sensors on E-bay for $69 apiece claiming to be new OEM and for '01-'02 sport trac 4WD. Would any of you guys put these on your explorers?

 

[brianwsnc]

Did you scan your system to see if any faults might be set? a guessing game for auto repairs can get expensive.

 

[cncman]

I have no way to scan.

 

[brianwsnc]

most all auto parts suppliers have scanners. I helps up sale parts, so they will scan for free

 

[LONO100]

before anything check the abs fuse1 ive blown mine beofre which will set the light off. is your speedo reading correctly? do you have 2wd or 4wd? figure out what type of sensor you have. that way it will be much easier to diagnose your problem.

 

[cncman]

No ABS light. Fuse 1 is good. Spedo is within 5 MPH according to those radar signs they put up near road construction. I have a 4WD. My only symptom is the ABS system triggering when it shouldn't. You could say it's hyperactive.

 

[rokr1292]

I've been having some abs problems, I have no idea what they are though, I pulled the fuse for the abs, because I was having problems in parking lots, which is bad. The problem is coming to a complete stop. On the brake below about 10 mph, it feels like the brakes let go, the pedal comes up and vibrates, and to stop I need to press down pretty damn hard. Without abs its prettty fine. Any ideas?

 

[LONO100]

holy smokes, i would guess its the sensors but im not sure. im only basing that on the fact that it doesnt happen when the abs fuse is pulled leading me to believe that the sensors are acting up. what i would do is find a place that will do a free brake inspection, then get their diagnosis and come back to the forum. ive seen the sensors on online parts sites for about 20 bucks a piece, you could try replacing yours and seeing if that fixes it. let us know what happens and good luck.

 

[ncranchero]

1. Standard OBD II/CAN scanners don't scan ABS codes. There ARE new scanners for the ABS that are becoming quite reasonable.

2.Sensor on rear differential is an ABS sensor which on some Fords also contributes info on speed. There is at least one, maybe two, sensors on the transmission that also indicate speed (see: output Speed Sensor)

3.The info from these is sent to the PCM and may in fact affect the things you mention. I have never experienced that but it's reasonable.

 

[cncman]

I took my Sport trac to my local auto parts store and they let me use their scanner. I think it was an Actron CP9580 or a similar looking model. It reported no problems of any kind. Looks like I'll have to give in and pay to have proper diagnostics done.

 

[brianwsnc]

Steve you da man!

 

[rokr1292]

holy smokes, i would guess its the sensors but im not sure. im only basing that on the fact that it doesnt happen when the abs fuse is pulled leading me to believe that the sensors are acting up. what i would do is find a place that will do a free brake inspection, then get their diagnosis and come back to the forum. ive seen the sensors on online parts sites for about 20 bucks a piece, you could try replacing yours and seeing if that fixes it. let us know what happens and good luck.

The abs light doesn't illuminate with the fuse in place, but the problem is there, wouldn't abs diagnostics only pick up things that would trip the abs warning light?

 

[LONO100]

that's why im suggesting getting it looked at by a pro. brakes are one thing i wont try to save money on if at first shot i cant fix on my own.this one sounds like a stumper because of the fact that the abs light isnt on but it is still malfunctioning.