clearing RABS codes, '93 Ford Ranger

[N8N]

Hi all,

Friend of mine has a '93 Ford Ranger that he'd given to his dad to drive, it came back with a laundry list of issues to be fixed, and I've been picking away at them. So far the only ones I haven't addressed are the loud and leaky PS pump, the horrible NVH from the ancient tires, and finally one that he wasn't even aware of and I discovered when I pulled the IP to replace all the dash bulbs (the high beam indicator was burned out, which would have been a safety inspection failure) - there's an ABS code and the ABS is disabled (as I found out when test driving the vehicle in the usual moronic DC-land traffic.)

I found these page

http://autorepair.about.com/library/faqs/bl583g.htm

http://autorepair.about.com/library/a/1d/bl492d.htm

and located the diag connector, grounded it, and read a code 12. According to that page, that code means "Loss Of Hydraulic Fluid During Anti-lock Stop" - well that makes perfect sense as sometime within the past year the rear hose blew out (possibly during hard braking? I wasn't driving it at the time) and I ended up replacing both it and all three hard lines connected to it, as they were too rusty to save. So theoretically if there are no other faults, I should be able to reset the code and have working ABS again. Unfortunately the only information I can find on *resetting* the codes is to turn the ignition off with the diagnostic connector unplugged. I've tried it both with and without the black/orange wire disconnected and the code persists. When turning the key on, the ABS light comes on for a bulb check, goes out for a couple seconds, and then comes right back on without even starting the engine or moving the vehicle. I can only assume that either the code chart that I found is incorrect, or that the code reset procedure that I found is incorrect.

Or is that page incorrect and the last flash shouldn't be counted, in which case I'm reading a code 11 instead? That would imply a brake switch stuck closed; however if it's the same circuit as the brake lamps (that is, not a double pole switch, or a separate switch from the brake lamps) then that's not the problem either as the brake lamps work normally.

Disconnecting the battery does nothing, as I have had it disconnected for days while working on it as one of the jobs to be done was replacing the engine and transmission mounts; the passenger side one is way too close to the starter to do that job without disconnecting the battery.

To be fair, this truck is a rolling pile of shit, but a running, reasonably safe rolling pile of shit is better than a driveway ornament, immobile pile of shit. And I like my friend's dad, I'd feel better if he had working ABS, especially on a nose-heavy vehicle like a pickup truck.

Any help gratefully appreciated...

nate

[N8N]

Never mind, as per usual seems like asking for help immediately precedes a "eureka" moment... anyway a little more googling on Code 12 in particular led me to the knowledge that that code does NOT mean what one would think that it means, that is, that the differential pressure switch tripped during a braking event. Apparently all that it means is that the master cylinder fluid level switch is reporting that the fluid level in the MC is low. *shrug* makes sense to someone I guess.

Anyway, I googled a little more and found what wires to jumper together to fool the system into thinking that the fluid level was OK (the two that aren't black, in case someone else finds this thread and has the same problem) boom, no more ABS light. Took it for a spin around the block, no slidey slidey. Came back, popped the top of the MC, stuck my finger in there and jiggled the float a couple times, reconnected the wires properly, still no code. Apparently it was just a stuck float switch...?

Now why the fluid level sensor triggers an ABS light and not a red base brake light, that seems (expletive deleted) stupid to me, but it is a Ford after all.

nate

[Brent]

Because the ABS pump probably requires a minimum amount of fluid to
operate without causing a problem while a leak would be detected by the
old fashioned switch between the front and rear.

[N8N]

I guess I could see that, but traditionally if there is a level sensor it's tied to the red light so I would assume that it would cause either a red light or the red brake and amber ABS lights to come on together... not the ABS light alone. Whatever, it's "fixed" now. Ready to hand back unless they want the tires and PS pump fixed. Just ordered new springs for the Heep today so it's not a moment too soon, between actually working as a pro wrench (frustratingly, in a shop in MD - a state with no annual safety inspection - with a rather less than affluent clientele, so I don't actually get to *fix* anything, just do a lot of oil changes it seems. I used to think safeties were an unnecessary PITA but I'm revising my opinion based on the complete lack of self preservation instinct that I'm seeing on the part of the average vehicle owner...) for the last month and everything around me breaking, I've about had my fill of working on cars for the rest of my life.

[T0m $herman]

On 1/20/2014 6:05 PM, N8N wrote:
> I used to think safeties were an unnecessary PITA but I'm revising my opinion based on the complete lack of self preservation instinct that I'm seeing on the part of the average vehicle owner...) for the last month and everything around me breaking, I've about had my fill of working on cars for the rest of my life.

After having brakes fail on a couple of vehicles, a wheel come off [1],
a tire tread separate completely from the sidewalls, and a anti-roll bar
bracket break and the bar impale the tire sidewall, I feel rather blasé
about mechanical failures on cars.

I must be riding motos too much, since even near misses do not bother me
much, other than people who tailgate - they deserve this treatment:
<http://www.youtube.com/watch?v=N5I7lXV9b88>.

[1] Pot metal wheel on a relative's Renault R5 had the holes enlarge
enough that the wheel came off *over* the lug nuts.

--
T0m $herm@n

[N8N]

While it's true that situational awareness and experience can get you out of a lot of bad situations with minimal damage, I prefer not to count on that... my point was that I too have experienced mechanical failures... the latest was the brakes on the Heep. I'd visually inspected them literally a week or less before they went out and saw nothing wrong. I'm guessing what happened was that one piston was stuck in each of the rear wheel cylinders, so at some point when I braked hard one of them freed up and started sucking in air around a now damaged seal. In any case, replacing the wheel cylinders (and shoes, hardware, hoses, and drums, since I was in there) restored proper braking.

The lesson from this, I guess, is when inspecting old, questionable drum brakes, have a helper gently press the brake pedal slightly with the drum off to move the shoes off the anchor pin, then "shake" the shoes slightly side to side to make sure that both pistons are free in the WC bore. I didn't do this because I was working by myself, and I did in fact peel back the boots and inspect for leakage and saw none at that time. Live and learn.

The *point* is, that if a vehicle can have a failure after passing a recent visual inspection, how crappy must the vehicles drive where I can just look underneath and immediately identify several problems that I'd consider to require immediate correction? (loose ball joints/tie rod ends/bushings, worn out wheel bearings, leaking brake components, etc.) But people will appear completely unconcerned about these issues and usually respond with "Thanks for letting me know, I'll come back another day" which seems to usually be code for "I'm just not going to bother fixing it, the car still moves under its own power."

nate

[rocxyl...@gmail.com]

Thank you so much for the tip on this the 2 that were not black i just removed from connector and taped them togeather and grounded the black one to the frame of the truck and no more abs.... oh yeahhhh.... thank you so much.... haha haha.... i love it..... stupid switch must be bad....

Thanks again for this info.... i love the internet when people give great advice....

Rocxy...@live.com