Diagnose and fix cruise control not working on GM vehicles
The infamous GM ignition switch failures can show up in many ways. One that baffles many people is when they the cruise control not working along with the ABS light on and the Red brake light on. The key to diagnosing the issue is when you find there’s no power at fuses 44, 48, 39, 51 and 52 in the rear fuse block.
Check power at base of steering column
Disconnect connector C201 at the base of the steering column. With the key in the RUN position, check for battery voltage on terminals D1 and B5. If you detect LESS than full battery voltage at D1, check voltage at B5. Both should have full battery voltage. If not, replace the ignition switch
Replace ignition switch
Disable airbag system and wait for it to power down
Remove the hush panel and knee bolster
Remove the steering column trim covers
Insert the key and turn to RUN position.
Push a hex key into the hole on top of the lock cylinder and push down. Pull the lock cylinder straight out.
Use tool J42759 or another tool to release the lock tabs holding the ignition switch in place.
Pull the IGN switch out of the lock cylinder housing. Disconnect the electrical connector
DO NOT ALTER the position of the GEARS between the lock cylinder and the ignition switch. You MUST verify that the gear is in the proper position before installing the new switch. If you don’t, the misalignment will cause the switch to remain in partial ON position and drain your battery. Insert a screwdriver and turn the gear to align if you’ve moved it.
Insert the new IGN switch and make sure the tabs lock into the lock cylinder housing.
Once in place, use a screwdriver to operate the IGN switch to confirm it’s aligned and working properly BEFORE you reinstall the lock cylinder
©, 2018 Rick Muscoplat
Posted on by Rick Muscoplat