Good news!...and bad news...mostly the ABS being a pain in the a**
 

So I got my deal with the '97 F250 straightened out, the one with the rebuilt title from my earlier thread.

She passed all the major parts of the checklist, but will win no beauty contests.

Aaanyway, the title came from Alaska and in order to have her retitled here in Georgia she has to pass a systems checklist by the DMV. The p.o. had attempted the test but failed on ONE topic, that F****** ABS light.

Now I am not out of the realm of getting behind the gauges and wiring the ABS bulb into something else, say the e-brake warning bulb just to pass the systems check, but I want to know what is going on.

P.O. says these items have been replaced:
Rear diff. sensor
ABS control valve
Fuses are good, I checked them.
Wire connections seem to be good all the way down the frame rail to the sensor.
Also he says it wont give a code when he had it scanned.-now this could be due to improper equipment or operator error.

Honestly since there is only ONE speed sensor, and ONE control valve, and ONE fuse what else can go wrong? What else could be causing that light to come on and stay on? Could it be the ABS control module? How do I test the module? ....and (dumb question of the day) where is it?

Should I have it scanned at the Ford place?

BTW, it does the little automatic syst. check when you turn the key, when you fire it up the light usually goes out, BUT just as soon as you let off the brake to back up or pull forward, it comes on and refuses to go out.

Any help would be greatly appreciated! This last step and she is mine :)

Prob a odd question, (I have my reasons though) but does it go off if you put the turn signal on? Check all your lights and make sure they are in working order. Even third brake light. Does it have any LED bulbs?

There is a two pronged plug just to the right of center, just under the dash. With the key on and the abs light on, it will put the abs computer in diag mode. This will flash out codes using the abs light.

The abs module is stand alone and not connected to the diag port at all iirc.

Richard

Edt... You short the terminals with a paperclip or some wire...

All the lights function, turn signals, headlights, low/hi beams, tail lights brake lights, etc.
No leds, no aftermarket lights except for some license plate bulbs which are incandescent.

What does it mean if the thing just stays on constantly? There is no flashing, it is just on all the freakin time when ever the truck is running.

Use the jumper mentioned above to pull the ABS codes and you can use the link below to decode them.

1996 Bronco/F-Series Workshop Manual

Go to section 06, then 06-09A, then click on "Symptom Chart" in the Diagnosis and Testing section. That has the troubleshooting steps and links to the pinpoint tests you will need to figure out what is going on.


If they have, indeed, replaced all that then the only things left are the wiring and the ABS controller itself. I would try swapping out the controller if you have access to one to try or can find one used for cheap.

Also, for what it's worth, if you unplug the ABS controller behind the glovebox, the light will go out and not work any more. Don't ask me how I know this, lol.

This is going to be my suggestion as well....that or take out the bulb and move on...LOL

^^^^ Would probably still fail the inspection, the same as if it were on. If it doesn't come on during the key-on bulb check, they'd fail it for that.

I kinda wondered about that...

Wow, seriously? That blows...

Thanks for the responses guys. I went this afternoon and had it tested, they said the ABS control valve (directly under the drivers seat on the frame) was bad. This is a remanufactured part that the P.O. installed. Are they particularly bad about failing when remanufactured?

Also here is my sneaky back up plan:
Pop the gauge cluster out, cut the wire going to the ABS light bulb, and tie it into something like the brake light bulb or battery light that comes on when you turn the key but off when you start the truck.

That way, the ABS light will be drawing from the same power coming from one of the systems that IS functioning properly. Since they DO check to see if it comes on at all.

Or you could fix it the correct way so your brakes work the correct way. That way your rears won't lock up on a panic and leave you doing 360's in the road.
Just my .02

Yes ultimately I would like to have it fixed right BUT I did the moron test last night and the ABS system DOES work, trust me :)

btw moron test = get out alone on a 2 lane hwy get up to about 45mph and try to stop the beast on a dime. you can slightly feel the ABS system working.

So I just went out to the parking lot and examined the sensor on the side of the brake pedal very closely (stopswitch or something like that). Unplugged it, and shorted the 2 prong recpt. wire going to it. Turned the key for dash lights, ABS light came on, then went off. Fired the truck up, that ******* stayed off. Stomped on the brakes a couple times, STILL off. Scootched it back and forth in the parking lot some. still off.

Havent hooked it back up, still has the jumper wire stuck in it.

I am assuming the short initiated some sort of reset? perhaps a step the p.o. overlooked when he replaced the rear speed sensor?

Hoping this has fixed it, will update soon, thanks everyone!

_Probably_ is the key word. Can't say for sure; inspections vary from state to state. But logic (which, of course, doesn't always apply with gov'ts...) would dictate that if an inspection would fail on a particular warning light being on, it would also fail on that light NOT lighting during the bulb check.

The "battery" light is actually a charging system failure warning light. And the light bulb itself is actually part of the charging circuit. Tying another bulb into the circuit might play cattywumpus with your charging system.

If you tie it into the red BRAKE (!) failure warning light, when the inspector applies the parking brake, the ABS light will go on with the red BRAKE (!) light, and s/he'll no doubt suspect something.

Moreover, there are no "wires" going to the bulbs. The bulbs go into a circuit board. You'd have to cut the corresponding wires on the connector(s) into the board.

As said, finding and fixing the reason the light is on is the most expedient approach.

That "sensor" is the brake pedal switch. Meaning, while it's jumpered, your brake lights are on. Driving around with your brake lights on all the time is as dangerous as driving around with no brake lights.

Yeah I just found that out with the brake lights.

So why does the ABS light stay off when the brakes are "depressed"?