DTC C1221, DTC C1222, DTC C1223, DTC C1224, DTC C1224, DTC C1225, DTC C1226, DTC C1227, DTC C1228, DTC C1229, DTC C1230, DTC C1231, DTC C1232, DTC C1233, DTC C1234, DTC C1235: Wheel Speed Sensor

C1221: LF Wheel Speed Sensor Input Signal Is Zero
C1222: RF Wheel Speed Sensor Input Signal Is Zero
C1223: LR Wheel Speed Sensor Input Signal Is Zero
C1224: RR Wheel Speed Sensor Input Signal Is Zero
C1225: LF Excessive Wheel Speed Variation
C1226: RF Excessive Wheel Speed Variation
C1227: LR Excessive Wheel Speed Variation
C1228: RR Excessive Wheel Speed Variation
C1232: LF Wheel Speed Circuit Open/Shorted
C1233: RF Wheel Speed Circuit Open/Shorted
C1234: LR Wheel Speed Circuit Open/Shorted
C1235: RR Wheel Speed Circuit Open/Shorted

Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK under DIAGNOSIS & TESTING. After performing diagnostic system check, go to next step.
Install scan tool. Turn ignition on. Set up scan tool snap shot feature to trigger for this DTC. Drive vehicle at speed greater than 5 MPH. If scan tool indicate that this wheel speed DTC is set, go to next step. If scan tool does not indicate that this wheel speed DTC is set, problem is intermittent. See INTERMITTENTS & POOR CONNECTIONS under DIAGNOSIS & TESTING.
Raise and support vehicle. Disconnect affected wheel speed sensor harness connector. Using a DVOM, check resistance across wheel speed sensor connector terminals. If resistance is 850-1350 ohms, go to next step. If resistance is not 850-1350 ohms, go to step 8 .
Manually spin wheel. Measure AC voltage across wheel speed sensor. If voltage reading is greater than 100 mV, go to next step. If voltage reading is not greater than 100 mV, go to step 8 .
Check for poor connections at wheel speed sensor harness connector. Repair as necessary. After repairs, go to step 10 . If connections are okay, go to next step.
Disconnect EBCM harness connector. Install Universal Pinout Box (J-39700) using Cable Adapter (J-39700-99) to EBCM harness connector only. Check wheel speed sensor circuits for open, short to ground, short to voltage or shorted together. Repair as necessary. After repairs, go to step 10 . If circuits are okay, go to next step.
Check EBCM harness connector for poor connections. Repair as necessary. After repairs, go to step 10 . If connections are okay, go to step 9 .
Replace wheel speed sensor. After replacing sensor, go to step 10 .
Replace EBCM. After replacing EBCM, go to next step.
Using scan tool, clear DTCs. Recheck DTCs. If DTC resets, go to step 2 . If DTC does not reset, system is okay.