ABS Anti-Lock error active, how to diagnose?

[crazyd]

My anti-lock dash warning has come on since my recent alternator adventure. I checked the connector in the passenger wheelwell where I was in there working thinking I might have knocked it loose, but an R&R didn't eliminate the error. Is there a similar paper-clip method of doing diagnostics on the ABS for a '92?

[RobertISaar]

no GM ABS system is that easy.... it's all scantool/ALDL cables for those. even then, it can still be a pain to figure out why a specific code gets set and won't go away. i eventually just unplugged the EBCM from under the dash and haven't seen the light on since then.

[Cutlass350]

Most GM ABS systems are easy and cheap to scan. But, between ~90-95, GM had a few odd-ball ABS system diagnostic connector connections. The Achieva's are a good example.

 

Check the ABS scanner manual to see if your year and engine are supported. There's an ~95% chance it is.

 

What ABS system do you have? IMHO, the Delco and Bosch systems often have error codes that are very easy to figure out. Of course, like with engines, you have to know and understand the ABS systems.

 

IMHO, it's always very foolish to replace parts without first reading the codes. Most code readers are cheap compared to the cost of most replacement parts. And, replacing a part when it's not bad is a complete waste of money.

 

 

Also, just because some low-cost code scanner only gives an error code, that does not mean that the system is hard to debug. It's rare that you need anything more than the error code to know what to replace on an ABS system.

 

Yes, having a data logger/scanner is very nice. It helps to confirm the error, and you can see the error happen.

Below is a data log capture of an example of the error condition when the Delco IV ABS system on my Achieva was bad. You can see how the Left-Front-Motor-Current-Feedback is reporting current, even though that motor was not commanded. I replaced the ABS motor packs, and the ABS has been fine ever since.

 

 

 

Good Luck!

Edited February 24, 2013 by Cutlass350

[douellette]

anyone have any links to some obd1 abs scanners? my gf's 93 regal has the abs light on, and now the brake light as well. I know it needs the rear brakes done because one caliper seized up.

[rich_e777]

anyone have any links to some obd1 abs scanners? my gf's 93 regal has the abs light on, and now the brake light as well. I know it needs the rear brakes done because one caliper seized up.

Rear caliper rebuild is easy, you can get a rebuild kit for about $10 and can get by without having to rent a special tool to remove the piston, just use an open ended wrench with a screwdriver acting as leverage, a dedicated brake shop should be able to scan the system. I personally am looking for one later for a similar issue with my ABS light but with no apparent malfunction.

[douellette]

Rear caliper rebuild is easy, you can get a rebuild kit for about $10 and can get by without having to rent a special tool to remove the piston, just use an open ended wrench with a screwdriver acting as leverage, a dedicated brake shop should be able to scan the system. I personally am looking for one later for a similar issue with my ABS light but with no apparent malfunction.

 

ive already bought a pair of loaded calipers, got them super cheap. didnt want to deal with the hassle of rebuilding calipers

[crazyd]

I got an Equus scanner here that said it would read GM OBD1 ABS codes, but it turned out it didn't support any W-body cars at all, just some trucks, vans and full-sizes. I found this one but it says it only supports 1996 & newer.

 

http://www.amazon.com/Actron-CP9449-BrakeScan-System-Diagnostic/dp/B000YJ053O/ref=sr_1_27?ie=UTF8&qid=1364865363&sr=8-27

 

None of my local autoparts stores have a scanner that supports it either. Has anyone found one that works for 91-93?

[douellette]

garage i went to had one, but it was a snap on (i think) so its expensive, but it was able to read the codes/clear em.

[RobertISaar]

actually, 89-91(i think) and 92-96 would be the year seperation for GPs.... 89-91 is powermaster 3, 92-96 is ABS 6.

 

the code reader you bought was nothing more than a paperclip. doesn't read anything ABS at all, it will only show DTCs from the ECM via the SES blinkout procedure.

 

that being said, the MC uses ABS VI and i've been reading codes off of it for years with my aldl cable before i finally just pulled the entire system since it hasn't worked right since ~1997 anyways.

[crazyd]

I have a forked "key" I normally use to read ECM DTCs on my OBD1 cars, but this device also purportedly would flash the ABS codes via pin H. I figured it was worth a try, but unfortunately it didn't work on my '92. I figure I'm in for $100 if I take it to a shop to read the codes, so if I can buy a reader for that much I've at least got something to show for it and I'm ahead of the game for the next time. Back in '03 I used to have a cable to hook up on a serial port of an ancient Win95 laptop to use Datamaster for scanning the ecm on my '92 TPI V8, but laptops don't have serial ports anymore and the usb/serial adapter didn't work with Datamaster somehow, so my scanning days went on hiatus.... until now.

[RobertISaar]

that pin H trick was VERY limited in what applications it worked on.

 

if you still have that cable, i can point you to a USB adapter that will work for you.

[Cutlass350]

There are a few scanners that can read the ABS codes for the GM odd-ball years/models/makes.

But, *I* don't know of any below ~$500.

Most go for ~$1K+, used on ebay.

 

You have to be very careful with the ABS readers and make sure that your year/make/model is listed in the user's manual.

If it is not, then, there's a good chance that the ABS reader will not read the odd-ball years/models/makes.

 

IMHO, getting a china-clone Tech2 is the best/cheapest solution now, since they are now just under ~$600 shipped. When I got mine a few years ago, they were still ~$1K+.

IIRC, it takes approx 1-3 weeks for delivery. IMHO, don't buy from a place unless they accept paypal.

 

Again, I'm talking about a Tech2 clone, not the real deal. IMHO, fine for the DIY and the occasional use. Not good for a garage.

Edited April 2, 2013 by Cutlass350

[Cutlass350]

FYI:

 

Snap On MT2500 Scanner:

http://www.oldsmobileforums.com/forums/showpost.php?p=60011&postcount=8

 

GM Tech2 China *Clone*:

http://www.oldsmobileforums.com/forums/showpost.php?p=60033&postcount=10

 

 

I would think that the snapon scanner "should" be able to read the ABS codes for the GM odd-ball years.

 

Good Luck!

Edited April 2, 2013 by Cutlass350

[crazyd]

Thanks Joe, I have used that MT2500 scanner before at a shop where I worked when I was building my V8 Fiero. I'm going to try to find my old cable for that car and see if I can make it work on my laptop with Datamaster first, then I may order one of those MT2500's. Rob, I'll let you know if I find it.

[Schurkey]

Snap-On MT/MTG 2500 works for my '92 Lumina.

 

A used professional-grade scan tool is far better than a new consumer-grade junk scan tool.

[Cutlass350]

A used professional-grade scan tool is far better than a new consumer-grade junk scan tool.

Absolutely!

However, IIRC, even a few years ago, you couldn't get a used Snap-On MT 2500 (with the modules/cables/etc) for under $1K on ebay. Now, they're are newer and better Snap-On scanners, that also support the newer cars/trucks and tests.

 

I got the scanner that I used for my above screen shot for a "low price" many years ago (over $500, IIRC) because it had a cracked glass over the LCD. It worked fine. But, who wants a scanner with a cracked glass over the display. That's a nasty accident waiting to happen.

I disassembled the scanner (not recommend unless someone has experience with laptop/tablet repair), took out the glass, and replaced it with Lexan. The scanner still works great, and I don't worry about glass breaking if I accidentally drop it.

[Schurkey]

However, IIRC, even a few years ago, you couldn't get a used Snap-On MT 2500 (with the modules/cables/etc) for under $1K on ebay. Now, they're are newer and better Snap-On scanners, that also support the newer cars/trucks and tests.

The first Snap-On scanner I bought was the MT2500; had domestic coverage up to 1999, along with the OBD II cable and some keys, and a multitude of OBD I cables. No Asian or European coverage at all. I think I paid $400 for it, and this was in about Y2K or thereabouts.

 

That scanner was destroyed in a garage fire. The insurance company gave me a settlement check, so I bought the second Snap-On scanner about 2004, an MTG2500 (additional Graphing capability) and domestic cartridges good to 2001. I paid about $1K, but prices are less now.

 

The third scanner was an MT2500 with the CAN 1B adapter, and domestic and Asian coverage good to 2005, I think. Had about the same cables as the others I bought, plus some Japanese cables. I paid less than $400 for it about two years ago. I bought it for the cartridges and the CAN1B, kept the cartridges and CAN1B adapter, and sold the body, case, duplicate cables, and the 2001 cartridges for just under $300.

 

Prices have come WAY DOWN for the MT/MTG 2500. They're not much more than the better consumer-grade junk, and do three times as much diagnosis IF YOU GET ONE WITH CARTRIDGES NEW ENOUGH FOR YOUR VEHICLE.

 

At this point, I'd be willing sell the MTG 2500 and pick up a Solus Pro or Modis instead (but who wants a fully-equipped MTG2500? I wouldn't get 1/3 of what I have in it--so I might as well keep it. It's current for every vehicle I own.)

[crazyd]

Update on this, I ended up acquiring an MT2500 on eBay; then the ABS light went out on its own, probably out of utter fear. I pulled the engine out late last year for an oil change (doesn't everyone??) and it went back in this Spring; ABS light is back on now. Does anyone know what cartridge for the MT2500 will scan the ABS on a '92 (ABS VI) that I need?

[Schurkey]

Does anyone know what cartridge for the MT2500 will scan the ABS on a '92 (ABS VI) that I need?

There are some goofy cartridges out there; as if Snappy used them for demonstrations; or deliberately loaded "light" versions of their software.

 

HOWEVER, any primary cartridge that is suitable for the '92 model year should also scan your brakes. It'll be in one of the menu options. If you have the companion troubleshooter cartridge, that'll be nice--but not actually required.

[crazyd]

There are some goofy cartridges out there; as if Snappy used them for demonstrations; or deliberately loaded "light" versions of their software.

 

HOWEVER, any primary cartridge that is suitable for the '92 model year should also scan your brakes. It'll be in one of the menu options. If you have the companion troubleshooter cartridge, that'll be nice--but not actually required.

 

I could swear I've been through all the menus already, but I haven't been able to find it yet. I'll look again. I have both a primary scanner cartridge and a troubleshooter cartridge for GM ~1988-93.

[Schurkey]

 

The first screen after entering the VIN information is where you select engine, trans, or ABS data. Some vehicles don't provide trans data, so of course the scanner is limited to what the on-board diagnostics is intended to output.

Edited August 28, 2014 by Schurkey

[Turbocharged400sbc]

ill nevar get rid of my red brick!

 

i have the adaptors for everything lol

[crazyd]

Figures as soon as I start making progress on this something else would go wrong. The clutch fork stud snapped on Friday, and who knows what kind of damage that did, so the engine's coming back out again. I'll circle back to this after I fix it.