Brakes sticking when warm (solved - pedal interference)

[luxuryrules]

Might as well sticker shock myself now - Mickey if I am in for an ABS module, what’s the availability like on those? A brief search from my end shows discontinued/unavailable from the usual GM vendors, but I think I see in your other posts you’ve got leads on the hard to find stuff. At least want to know what I may be in for haha.

 

[mickeytee]

Not bad you can find them used for a couple hundred dollars . get the module and manifold plate together.

 

[luxuryrules]

Well, that’s curious. Got the tech2, connected via the 26 pin connector on the bottom, via the Candi interface block, to the little adapter from the 19 pin round connector to the OBD2 connector. Tech2 plugged into wall outlet. Car in accessory mode, I can scan for DTCs in most of the options menus but get “no communication with EBCM, check ignition status” if I try to look for ABS codes.

1- am I connecting this correctly?
2- does this confirm a suspect EBCM, assuming wiring harness is ok?
3- shouldn’t I have seen an ABS light on the dash?

 

[justdennis]

First I don't think you are supposed to plug it into the wall outlet when it's plugged into the OBD, it gets it's power from the car. Assuming you followed the manual and did the initial hardware installation you should be good to go. I would start the car then turn on the Tech2 and try it again.
I'm not sure what's causing your problem but from my experience a very high percentage of the problems with these cars is caused by loose connections or bad grounds so I would start there before you spend a lot of money. Good luck, keep us posted on your progress.

 

[luxuryrules]

Thanks! The little booklet (or at least the only instructions I can find online since mine didn't ship with a paper manual) confirms not to use power jack when DLC is connected. Whoops.

Repeated test with Tech2 > 26 pin to 19 pin cable > Candi module > 19 pin to OBD2 adapter and car in accessory mode (and my ctek hooked to the battery because I see there are a *ton* of issues caused by battery drain). Unfortunately same result, so I'll start examining harness and connections first.

Weird that I've moved from a brakes issue to troubleshooting a wiring harness

Edit: this is disappointing. I’m actually surprised I don’t get a dash full of lights and DIC warnings? The car came with an aftermarket stereo already installed so those three don’t surprise me, but things like the suspension controller I’d expect to trigger a warning.

 

[luxuryrules]

Now I’m getting somewhere. Helps if I’m in “key on engine off” I was in “accessory mode” before.

Got a C0710 - 52 and a C0161 - 11. Looking at the diag table for the 0161, looks like I’m troubleshooting the brake pedal position sensor.

 

[justdennis]

Easy mistake but that's why I suggested starting the engine, then you know everything should be operational. While running you can see real numbers. If you goggle 'Tech2 manual' you'll find one.

 

[luxuryrules]

Yep, found one - annd also confirm I made a mistake by leaving the ctek on my battery, it’s advised not to have a charger on the battery while using the tech2. I’m making every rookie mistake haha. I swear I’ve been working on cars for a long time, this is just a whole different beast than VCDS, INPA, and AlfaODB.

 

[lextoy]

Yes you need to be in ign on mode, not just acc mode. That's hold the acc button down for 3 to 5 seconds. I do diagnostics with the charger hooked up. Doesn't seem to have any effect. Keeps the voltage in a better range.

 

[lextoy]

Half my battle was figuring out the right order to powering up and plugging in the tech2 clone. Once I got it to communicate with the car properly, it was very helpful to check systems and clear codes etc. It looks like you aren't getting good comm. Yet.

 

[luxuryrules]

Testing BPPS and observed it wasn't returning to home. Found the kick panel wasn't secured properly, it was drooping down and one corner of the panel was hitting the brake pedal arm, keeping it from returning to home position.

Easy fix. Silly problem. Now I'll go sign the Wall of Shame Thanks everyone for your help and encouragement.

 

[lextoy]

Omg congrats!! It wasn't that silly. Took a tech 2 to find it. It's always a relief when you finally get to the bottom of something. Go have a brewski!!

 

[lextoy]

Now you have a nice xlr V, and a tech2. Two toys that most would love to be in command of.

 

[justdennis]

Great news, thanks for sharing what you found, we all learn from each other.

 

[mickeytee]

Great that you found it. That should have held your brake lights on as was asked about way earlier.