Fix code C1216 C1221 C1222 C1225 C1226 C1233 ABS light on Buick Century, Chevrolet Impala
GM has issued a technical service bulletin 03-05-008 PIC3500 to address the following ABS related trouble codes. C1216. C1221. C1222. C1225. C1226. C1233. Before you replace any parts or conduct any testing, first check the wiring harness. The harness passes under the front of the transmission side cover. GM reports that harness chafing can occur in that area because the powertrain flexes on its mounts (You would think after all of these years making vehicles, GM would know better). Check the harness for any signs of chafing. Next, examine the area near the A/C dryer canister where the ABS harness splits. The harness can chafe right at the dryer canister bracket. If you find chafing, remove the harness and repair the damaged insulation with heat shrinkable tubing.
© 2012 Rick Muscoplat