S4gunn

I drained the brake fluid in my reservoir the other day with a turkey baster and filled it with Honda DOT3 fluid and immediately afterward, my ABS light came on.

It won't go away after trying to reset it and after tripping the service connector light, it won't tell me what's wrong, either. Help!

Here's what I tried (Updated):
* Jumpered Service connector - ABS light stays solidly on (no blinking)
* Tried resetting ABS via pulling ALB2 fuse, disconnect battery, etc. = doesn't go away
* Tested motor operation by jumpering connections in fuse box per Helms manual. Motor works.
* Tested ABS motor relay with external battery. Works as expected.
* Drove the car up to 60MPH and brakes HARD. ABS does not engage (although my new rear pads and bedded in quite nicely).

I read the million and one threads in this forum on ABS and I haven't found anything that exactly matches my situation.

ABS Testing:
Q: Could air have gotten into the high pressure part of ABS system when I drained the Normal Brake fluid reservoir (in front of the driver) and would this air cause the ABS light to go on but NOT report any codes from the ABS ECU?

Possible Root Causes (near as I can tell)
* Air in ABS system?
* ABS ECU
* Blown underhood fuses [eliminated]
* Bad Motor Relay [eliminated]
* Bad Backup Relay [eliminated]
* Bad wiring
* Bad Motor (Suggested by friendly service advisor. Quoted $1200 to fix) [eliminated]
* Motor could have relief valve stuck open
* Pressure Switch
* Solenoid
* Power to ECU

From my standpoint, anything after the first item make it not worth fixing on this commuter car - I'll just disconnect the ABS brain behind the seat and forget about it. I've driven cars w/o ABS before so it doesn't bother me that this car wouldn't have it anymore either.

For the sake of completeness, here are the other things I've done in the past week which might have also "triggered" the ABS light.
* Installed a keyless entry system. All taps were into the ignition switch harness and the harness going into the security brain.
* Installed a K&N filter
* Replaced my rear brake pads LAST WEEK and used a sparse amount of squeak stop blue goo.

Any thoughts?
-g

__________________
2002 Audi S4
1994 Acura Legend L (commuter)

 

mondonalds

I would try bleeding the brake system. It may help, it may not but worth trying since its not too difficult.

__________________

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1996 Toyota 4Runner Limited (05-06 - _____)
1993 LS Sedan - Geneva Green Pearl w/ Type F (11/04 - 07/06)

S4gunn

So I know if I don't buy an expensive Air Bleeder T from Acura, I need an 8mm SQUARE socket from Sears and a bunch of towels, right?

Am I correct in this assumption:
From the Helms, it says the purpose of the Air Bleeder T is to measure how much aerated fluid comes out of the pressured system (the accumulator).
This is how you tell if you have a bad/leaky accumulator, right?

So in my case, if I just want the air out, all I need to do is bleed it off, wipe up the spurting fluid, and just tap of the ABS reservoir, right?

That's worth $5 or whatever for the socket.
-g

Q: Can I "overbleed" the system by any chance? How long do I leave the valve open?
Q: Are there any more ABS related fuses in the in-car kickpanel fusebox? I wonder if we pulled one by mistake in our quest for 12V constant + 12V Accessory.

__________________
2002 Audi S4
1994 Acura Legend L (commuter)

jno2968326

try removing the alb1, alb2 and alb3 fuses for about 1 minute.

S4gunn

Tried that already. Also left the battery disconnected overnight.
After spending Sat morning calling various independant mechanics, I found a reasonable mechanic who was willing to listen to the things I tried and offer suggestions *BEFORE* I brought the car in for a diagnostic.

All the other cheap s were "You want free advice? You bring car here we tell you what's wrong. You go now."

Vic @ Hondacraft's suggestion was that my brake fluid drain & fill had nothing to do with the ABS light. Since the motor/pump ran when I jumpered the connection, the didn't think that was bad either (which would have cost $1200 to fix according to the dealership). Vic's suggestion was that I should go ahead and check the wheel sensors and try resetting the system again. If that doesn't work, the diagnostic procedure as outlined in helms will include a high-pressure bleeding and will cost me $80.

For $80, its worth rolling the dice before i say "screw ABS" and yank the cables out of the ABS brain behind the rear seats. Plus, I'm pretty happy that I found a mechanic willing to work with me vs. just charging me to tell me what I already know (the ABS system doesn't work and the ECU doesn't report any codes).

-g

__________________
2002 Audi S4
1994 Acura Legend L (commuter)

S4gunn

Final Update: I found the root cause of my problem was a fuse installed incorrectly in the under dash box.

__________________
2002 Audi S4
1994 Acura Legend L (commuter)

Puffy

how is a fuse installed incorrectly? I ask because my light is also on, and for the life of me i can't figure it out either

mocca

S4gunn, I am curious about the fuse as well. What fuse are you referring to?

LPB

I also am puzzled re the under dash fuse. What exactly do you mean by incorrectly installed? Which fuse?

As to the high-pressure hose, my ABS was ok, until I had the hose replaced (as per HELM). Perhaps it is just coincidence. As to bleeding the ABS high pressure system, you need to be extremely careful as the brake fluid will eat paint faster than you read this last sentence.

__________________
Eyebrows
KMS Strut Bar
Enkei 16" J-Lips
Wings West Spoiler w/LED
Clear Corner Lens
Clear Bumper Lens
Clear Rear Side Markers
Brembo X-Drilled/Slotted
Stainless Braided Brake Hoses
Focus 2500 Driving Lamps
Gold Pkg

S4gunn

My ABS light didn't come on until I started screwing with the dash box during my car alarm install. When I first brought my car to the shop, they went through all their diagnostics and concluded that the ABS computer must be bad because a) ABS didn't work and b) the ABS pump tested OK but c) no codes were thrown. Looking at the wiring diagrams, I realized that the ABS light would disappear if you just unplugged the harnesses. This is what we did.

A few weeks later, I visited the mechanic for a second time because my A/C compressor was kicking on intermittently. The mechanic (correctly) quickly diagnosed that the Fan Control Unit (FCU) was bad and he just replaced it with a junk yard part. During his diagnostic process, he says "he noticed that one of the fuses was lose or not inserted correctly." Seeing as how I was becoming a frequent customer, he reconnected the ABS computer and Voila! ABS worked again!

This "misplaced fuse" theory is entirely possible even though I finally used a power point that was next to the fuse box entirely for my car alarm. I was originally looking for a place to get power and one idea was to use a fuse tap to get power out of one of the fuse sockets (I use this method to hardwire my Audi's radar detector). I did pull a few fuses and its entirely possible that I didn't insert them back in correctly (maybe one leg didn't make it into the hole or I put a fuse back in but didn't put it back in the correct socket). Since I didn't find that final fuse (at the time, I had already written off ever having ABS work again), I cannot explain it any better than this. My only suggestion is to look at the wiring diagram in the Helms manual and follow things closely.

A year later, my ABS still works. I did replace my Fan Control Unit a few months later but once I learned from my mechanic that the FCU controls the A/C compressor, I did this in 5 minutes myself.

BTW, 40K+ mi after my first post, I still haven't screwed with the ABS high-pressure hose. If its not broke, I'm not going to screw with it.

-g

__________________
2002 Audi S4
1994 Acura Legend L (commuter)