C221B on Jeep: How to Diagnose & Fix

C221B stands for "EDLFailSts Signal Not Valid From BRAKE7 Message." The Drivetrain Control Module receives an electronic-differential-lock fail-status signal (EDLFailSts) inside the BRAKE7 CAN message broadcast by the ABS/ESC module. C221B sets when that signal arrives invalid or implausible, so the DTCM cannot trust the brake-system status it needs to arbitrate the AWD disconnect/reconnect strategy. The common suffix is C221B-64 (signal plausibility failure). Important caveat from the FCA bulletin: on Renegade/500X this code, together with C2502-64, can latch Active *erroneously* simply because a scan tool interrogated the ABS module during a diagnostic session — FCA instructs the technician to disconnect the tool, drive the vehicle ~100 feet, reconnect and read All DTCs before starting any repair. It is therefore frequently a companion/secondary code rather than the fault itself. On Jeep it is documented across 1 model: Renegade.

The most common causes of C221B are: Fault or stored DTC in the ABS/ESC module that corrupts the BRAKE7 message, CAN bus wiring/connector fault between ABS module and DTCM, Erroneous setting during a scan-tool diagnostic session (documented FCA behavior — re-verify after driving the vehicle), Outdated DTCM software (addressed by DTCM reflash bulletins). The specific cause varies by vehicle.

Published repair estimates on Jeep range from $1,200 to $2,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.