Whoa...good one

Code 12:
Loss of Hydraulic Fluid for One Second or More During Anti-Lock Stop
(Most commonly fluid level is low)

Release park brake.
Turn ignition on and allow for self check.
If both yellow and red lights go out, apply park brake, if yellow light re-appears repair red/yellow wire. If red/yellow wire is okay, replace diode/resistor.

After ignition self check red light is lit and yellow light is off, check brake fluid level.

If after ignition self check yellow light is lit and red light is off...there is another problem..you will need to retrieve codes again.

 

How do you determine which one you have? I have 99 Lariat 5.4L 4X4, 4 wheel disc brakes.

 

Does anyone know WHERE the ABS control module is?

 

To piggy back on this thread, I have a situation ... 98 F150 2WD ... The RABS module was replaced maybe 3 yrs ago when abs light was constantly on ... now, my brake light and abs light comes on intermittently ... i notice once after a hard stop the lights came on ..I noticed a couple of time after a lot of stop and go braking the lights came on ... I have 184,000 mis on truck ... original master cyl, calipers and wheel cyls ... new front pads went on my May ... new rear shoes a couple of weeks ago ... BTW, I was seeing the lights before I put the shoes on ... When I turn vehicle off and start it again, the lights turn off as normal ... they sometimes, not always, but sometimes come on after lots of braking ... Anyone having an opinions or suggestions, please chime in ... Do I need an ABS light currently illuminated before I can try to jump the codes? Thanks in advance for any responses.

Steven

 

Under the dash, behind the radio/instrument cluster.

Steve

 

Look at your front wheel spindles. If there are any wires going to the hub, you have 4WABS. No wires, RABS.

Steve

 

Check your brake fluid level.

Steve

 

Thanks Steve ...yeah, I have check that. Fluid level is fine. My last flush was 2 yrs ago when I had the RABS replaced ( Mar 05 ... 62,000 mis on vehicle since then ). I was wondering if the mast cyl could be starting to fail and I am leaning towards replacing it when I flush the system. Is there any thing unique to flusing the system? I have a pressure bleeder. I assume that I will bench bleed mast cyl, install it on truck, then pressure bleed/flush the entire system going far wheel ending up at nearest wheel.
Still, I am open to any additional suggestions. Once again, thanks for the response ...

BTW, I am assuming that the ABS light is coming on because brake light is triggering it. That's why I
haven't opted to do the rear sensor replacement that is often applicable to ABS light. If my logic is
faulty here, please let me know.

 

I see that 688 people have viewed this thread. Doesn't anyone know where the ABS module is?

 

does anyone have a pic of the control modual that they can post????????

if not any ideas why my abs light comes on in drive and not reverse?

 

I'm not sure about the older trucks... but current trucks the control module is in the engine area. The ABS unit and control module are all one.

Here is a picture of what the ABS unit looks like

(its not from a F150, but they all look similar)

On the back of this unit is the wiring harness where all the sensors / power / etc tie in.

To find this on your truck - follow the tubes out of the master cylinder. They will lead directly to the ABS unit. It should be fairly close.

As far as why your light comes on in forward and not reverse... perhaps the ABS is not engaged when you are in reverse? You generally do not back up fast enough to need ABS.

 

Thanks I will look when I get home, and when you mean newer trucks do you mean year 94+ becasue I have a 91'

 

When you ground the 2 wires, are you using a jumper wire or what? How do you do that

 

Just searched and found this thread. Our 1999 F150 had the ABS light coming on intermittently. After reading this thread, I located the rear ABS sensor located on top of the rear diff pumkin. Checked the rear sensor with an ohm meter. Was showing no resistance. Bought one at AutoZone for $14. That solved the problem! The old one was covered with muck (there is apparently a magnet in it which picks up some crud over time). Thanks.

 

if the Sensor in the rear Diff is bad, will it cause the brakes to be soft or not work like they should.

Thanks 97f1 4.6