A Service Door Latch System message may be shown on the Driver Information Center (DIC) of some 2025-2026 Tahoe, Suburban, Yukon and Escalade models. In addition, the rear child door lock safety feature (Fig. 7) may be out of sync or mismatched between the left and right rear doors, resulting in malfunctioning locks. This condition may or may not continue over key cycles.
Fig. 7
TIP: On some 2025 Yukon models built before February 24, 2025, the Service Door Latch System message also will cause the Child Safety Lock On/Off buttons to be inoperative due to a calibration issue. Reprogram the A11 Radio for this condition with the latest USB and SPS calibrations available in Techline Connect/Service Programming System. The updated calibrations will enable the Child Safety Lock On/Off buttons during an error condition.
On all models, the Body Control Module (BCM) should be reprogrammed with the latest calibrations listed in SPS.
After reprogramming the BCM, try to resync the rear door child safety locks by first opening all doors, leaving them open, and then cycling the child safety locks on/off using the controls on the infotainment screen. Go to Controls > See More Controls > Doors & Windows < Child Safety Locks > On and Off. (Fig. 8)
Fig. 8
TIP: There are two different menus on the infotainment screen where the child safety locks can be cycled on and off. The locks must be cycled from the screen shown above or it will not cycle the child safety lock actuators, which will be shown grayed out.
Turning the child safety locks on/off will cycle the rear door child safety lock actuators and, if out of sync, will bring them back into sync with each other and clear the DIC message.
Child Safety Lock Synchronization
If cycling the child safety locks resolves the concern, advise the customer that the condition may have occurred if the child safety locks were turned on or off while someone in the rear seat was pulling on the interior door handle. Performing both actions at the same time can cause the system to go out of sync. If this condition occurs again, fully release both rear interior door handles and then cycle the child safety locks off and on again using the infotainment screen control to restore proper synchronization.
If cycling the child safety locks does not correct the condition, check to see if both locks are synced together. Using GDS2, view BCM > Data Display > Vehicle Access Data and monitor the following two parameters: Right Rear Child Security Lock – Lock Command and Left Rear Child Security Lock – Lock Command.
Out of Sync Locks
Some reasons that the rear child safety locks may not be synced with each other include:
- The child safety lock feature may not function properly and go out of sync if there is preload on the door latch caused by the inside door handle or cable. This preload can result from an improperly installed, binding, or kinked inside door handle cable, or from the inside handle being pulled, creating slight tension on the latch. Even a minimal amount of preload may prevent the child safety lock from engaging or disengaging when cycled. To ensure there is no preload on the door latch from the cable, remove the interior door panel on the affected door and disconnect the door latch cable from the inside door handle. While the cable is disconnected, turn the child safety locks on and off as outlined above to restore proper synchronization. If this resolves the concern, reconnect the inside door handle cable, ensuring it is correctly routed, free of kinks or binding, and properly connected and fully seated to the handle assembly.
- An issue with the feedback circuits 3269 or 3268 (see example Doc ID 6614043 in the appropriate Service Information).
- A fault with the child safety lock actuator circuits 3266, 2679, 2680 (see example Doc ID 6614044 in the appropriate Service Information).
After the fault is found and corrected, cycle the child safety lock feature on and off to resync and clear the service door latch message.
For more information, review normal Service Information diagnostics for Power Door Child Lock Malfunction and #PIT6288.
– Thanks to Mark Shearer
