[Uncko Macko]

I found a thread last night with a GM procedure on bleeding the ABS module with a Tech II but now I can't find it. It starts by listing 3 cases where it is required. Number 2 being fluid loss or air sucked into the system. Anyone have a link to that procedure??

I had my Calipers powder coated and now I have a spongy pedal and the ABS light is on. It's been bleed repeatedly, key cycled, calipers are on the correct sides, connectors and wires look good and no codes.

Thanks,

-Mike

 

[GOPHERIT]

I can't help finding it either (very bad at using search header). But that means you've come to the conclusion, that air is trapped in or above the EBCM module. I see the TECH II runs a program that opens up the 4 solenoids. Then when fluid is bled out thru the bleed valves at the wheels, it will also force any remaining air anywhere in the system out along with it.
The TECH II most likely is the only way possible to energize those solenoids for an extended period, to accomplish this procedure. Yes the solenoids are cycled at some point after the start of each ignition drive cycle, but there cycle on time is just long enough to verify that they are operational (if required).

 

[Eidolon]

Yup, it's called a "Tech II bleed" because, unfortunately, it uses the Tech II dealership computer interface system. So unless you spend the money for the handheld tool yourself - which is several thousand dollars - pretty much your only recourse is to take the car to the dealership or find a specialty shop that has the tool.

 

[Uncko Macko]

Got it...It ended up being a loose pin in one of the speed sensor connectors.

 

[GOPHERIT]

Well, you've lost me on that post. You had a ABS fault lite with no codes set (doesn't sound right), but found a problem with a speed sensor connector (fixed), an it corrected the ABS lite (which makes sense) and your spongy brake peddle problem disappeared like PFM. That's amazing.

 

[Eidolon]

Well, you've lost me on that post. You had a ABS fault lite with no codes set (doesn't sound right), but found a problem with a speed sensor connector (fixed), an it corrected the ABS lite (which makes sense) and your spongy brake peddle problem disappeared like PFM. That's amazing.

When the problem is a busted wheel speed sensor, the computer in these cars doesn't set a code that can be read by a standard OBD code reader. It would require a Tech2 system because it's a vendor-specific code. It does throw the warning light, though. So fixing the loose plug would indeed get rid of the code.

As for the spongy brake pedal, you're right that fixing the speed sensor connector won't do a thing for that.

 

[Uncko Macko]

Bled the brakes a few more times and the pedal got better.