GM has issued a technical service bulletin for Buick Rainier (05-07), Chevrolet TrailBlazer (05-08 ), GMC Envoy (05-08 ), and Saab 9-7X. The TSB #07-05-25-006 relates to a problem with the ABS system and results in a scan code C0040. GM advises you to inspect the right front wheel speed sensor for damage caused by rubbing against the A/C pulley. If you find damage, wire in a splice and then reroute the wires away from the pulley.