I know the C5 has a few Control modules, how many are repairable ? And how is able to do the repair work ?

 

I have fixed about 4 of the ABS modules for myself and other friends. Each one of them was old / cold solder joints on the electronic board where it meets up with wiring harness . It gives you all kinds of weird error codes for ABS and active handling, but that's what it has been. I take it the module out of the car, remove the cover from the module then I take it to a TV repair shop to have them ho over the solder joints. It's pretty easy once you've done one, there are very good procedures written by members of the Corvette Forum here that will help you immensely.
Taking the module out isn't very easy, seems like you need double joints in your arms. Removing the cover may take a couple of hours the first time because it's glued in place with a rubber water proofing caulking type of stuff. There's a specific hole already in one corner of the cover and you install a long thin bolt ( I think it's a 10-32 by about 1 1/2 inch long. ) and turn it in and it pries up one corner of the cover enough that you can pry up the rest. It's scary the first time you screw that bolt into what could be the electronics, but it works. Finding a TV repair shop in business is the next trick. Nobody has their TVs repaired anymore, we all get a newer, bigger TV at Costco.
Go to a used car lot and ask who fixes their ABS modules. Take your module there and ask him to do the soldering on YOUR MODULE. I don't want someone else's module, I want mine back! You might just have that guy take the cover off also. All newer cars have these ABS modules and 99% of them just need soldering . A used car dealer is not going to spend $2,000 to have one repaired . There are people that do this locally.
I have had one problem with the right door control module, the door lock wouldn't work from the drivers door side control switch. It ended up being a bad connection in a quick disconnect connection in the right door for the ground connection. Module was OK.

Good luck,

Mike

 

For the modules that can be open up, you can easily replace any thru board mounted components that may be bad. That said, most of GMs modules have unmarked and unlabeled transistors, diodes, regulators and surface mounted components. There are ZERO schematics for the inside module circuitry, so you are left with basic component testing and measurements. If a component is bad, good luck figuring out what value it is unless you have a good module to test its value.

If a module indicates that it is NOT WORKING/ communicating, the very first thing that needs to be tested is: Proper Battery Voltage on ALL of the module 12VDC battery / ignition voltage inputs. Proper module power GROUNDS on all of the module grounds to chassis /battery ground. I always test the 12 VDC inputs with a LOAD to make sure that there is proper current being applied to the module. You can test Voltage and load on the fuses to each module. If you load the circuit down, the battery voltage should not drop below actual battery voltage measured at the battery. On top of each Fuse are TWO TEST POINTS that you can put the meter probe on to test voltage. .
NOTE! Some modules have MULTIPLE 12 VDC power inputs and multiple grounds. The GM Service manuals have very good schematic diagrams that show voltage inputs and grounds for each module. Example: The BCM has at least FOUR 12 VDC fused inputs. Some hot at all times and some Hot When Ignition is ON or ACC.

Many of the module failures are due to cold or broken solder joints or in some cases, some of the Electrolytic Caps can dry out and go bad!
NOTE! It has been theorized that leaving the car/battery continuously connected to a battery charger, pumps DC square wave voltage into the modules that are on/in (sleep Mode) i.e. PCM/BCM,& RFA Modules. That Square wave voltage can adversely affect the electrolytic caps causing to them to dry out/break down.
True battery voltage is true DC voltage without square waves and has fewer damaging effects on the Caps.

Before you get too involved in component replacement, I recommend carefully inspecting the circuit boards and looking for cold/damaged solder joints and any white powdery corrosion that can form on the board circuit traces between circuits due to moisture/water exposure.
Some modules have RELAYS that go bad. The relays can be sourced aftermarket. Example of some modules with relays are: The Left and Right Door Control Modules and the EBTCM. The EBTCM is well known for damaged, broken, cold solder joints and bad power relays!

Good luck.

BC

 

Thank you Sir !