I’m a firm believer that there are no stupid questions. I have checked the parking brake to make sure it works when pulled up and releases when pushed back down. I use it frequently when I park and seems to be good. I’ll check the switch as I haven’t checked that. Need to research that. Thanks!!

 

Alright, I have some more updates. It seems someone must've had a reason to take off the ABS module connector or it was hit because the bottom piece of the connector was cracked off. I flipped up the cover and tried to push it back a little too hard (thought maybe it was a lever to break it free) but just ended up breaking the small plastic piece a little at the top. I then discovered that the trick to getting this off is to lift up the cover flap on the hinge, and then pull that cover piece up which will pull up small pieces of plastic on each side of the ABS connector then allowing it to come off. I got it off!!! I then tested the ground wire for continuity on two different ground points around the driver wheel well and all grounds tested good. Voltage also look good. The bottom external wires (not internallly) were dirty where the previous person broke the bottom piece of the cover connector leaving them exposed, but didn't seem to impact the connection.

I called Repair Laboratory that you shared, Oldblue, and they wanted $600 to repair it no matter what the repair consisted of. That's not a fair price at all IMO so I will look to pickup a used one and then have it programmed. Several other places like Upfix, Module Masters, and Circuit Medic Boards said they can't get the parts for this ABS module so won't be able to work on it or even look at it.
Anyone had much success getting these used units programmed with a new VIN? I've read conflicting reports on whether flashing it will work if it's locked or not.

 

I’ve seen folks here try to save a buck and ending up spending more. It’s an obsolete part, so if you find another in a parts yard, it’s just as plausible it’s in the same condition or worse or better. Do you feel lucky.
Im a big Clint Eastwood fan.
my local GM dealerships all said they can’t connect to a 15 year old car their systems won’t interface properly.

 

They lie. OBDII has been OBDII since 1997 and CAN-Bus is still the standard.
True they don't use TechII anymore, but the new computer software (MDI2) uses the same programs (SDS)..

The technicians just don't know how to use it.

 

Yesterday before the winter storm hit, I went to a local junkyard and found the exact part from another 2010 HHR for dirt cheap. However, I ran into another problem. The reason I've had such a hard time getting the ABS connector off is because where it is located; it's right under a hose blocking the plastic lever connector from coming all the way up which in turn slides the plastic pieces up and releases the connector. On top of that, the top corner of the ABS module is right under the ECM connector with no clearance at all. I can see where a piece of the plastic ECM connecter was broken off previously when someone must of have been doing some work so it's been like that since before I got it. I can only imagine it was either installed that way from the factory or it was hit/bent at some point in it's history that positioned the ABS module under the hose and right next to the ECM connector. With that said, I still managed to get the old one off with a lot of pushing and pulling and managed to get the junkyard module back on with even more pushing and pulling, but I won't do that again since I think I was putting too much pressure on the ABS module housing/pump brackets and the ECM heatsink. I was really optimistic things would be better with the junkyard module in, but now I have the vin mismatch, same C0550 code, plus one front right wheel speed sensor is failing consistently and not showing any live data (stuck at 0). I'm going to put my original ABS module back in and see if the wheel speed sensor error goes away. Either the new module has a bad right front speed sensor channel or maybe I bent a pin or it's not seated well when I was plugging in the connector. Next time I do this, I will most definitely find a way to get the ECM module out of the plastic slot since that will give me the clearance I need to easily (and safely) get the ABS module uninstalled/installed. I looked and felt everywhere for what was holding the ECM in the plastic mount but couldn't find it. I will try a camera in there to see if I can see where it's secured. I just looked in the shop manuals and it looks like there is a single retaining tab that is holding the ECM down in two places that I need to release somehow. I "think" I need to pull it towards me and away from the ECM module, and then I can slide it up and out and get the clearance to make ABS module work much easier. The junkyard also had one more exact ABS module which I can swap out for in case this one is a dud. Feeling lucky?! Fun times!!!

 

I just used a lot of force to defeat the tab.

 

Ha! I did try to remove it using just my hands, and it would wiggle freely forward and backward but wouldn't budge when trying to raise it out. Now that I know where those tabs are, I will focus there and see if I can get it to release (once it get's a little bit warmer).

 

Another update... I was able to easily tilt forward the ECM enough where it disengaged the bottom tabs and it come up with no problem. Made the ABS module remove and replace procedure much, much easier. I put the original ABS back in and it showed all 4 wheel speed sensor codes plus C0550 at first but then settled at only the C0550 code so I don't think anything is wrong with the wiring harness connector, the wire pins or the wheel speed sensors. It's very possible the unit I got from the junkyard also failed. I've read online these GM ABS modules fail a lot. The fact that no one will repair them (for a fair price) due to a shortage of parts tell me either it's complicated to repair and they know it's a chip replacement (not just a resolder), and/or the rate of failure must be high and they don't want to warranty them. I did get good news from my local GM dealer; they can program a replacement module for 1 hr of labor. Now I just need to find an ABS module that doesn't throw the C0550 code and then have it programmed. I've already verified ground continuity at the wiring harness and good voltage so don't think it's a ground issue.

 

Whatever the reason that’s the price they charge. Try getting the retractable roof module for a Cadillac or SSR

 

FWIW, you have to drive a few hundred yards to activate the wheel speed sensors, or you will have those codes.