The GM Accessory Power Tonneau Cover (part number 86575628 or 86595165) is available on 2022-2024 HUMMER EV Pickups. (Fig. 15) If the hard power-retractable tonneau cover is not operating properly, check out Bulletin #24-NA-028, which has a number of diagnostic tips and adjustment procedures to help with repairs.
Fig. 15
Installation Assistance
There are several installation videos available in Service Information for the HUMMER EV. (Fig. 16) To view helpful tonneau cover installation procedures, go to the Pick Box Cover Package Installation (Power Tonneau Cover) in the Accessories Manual.
Fig. 16
During installation, be sure to avoid poor wiring issues that can lead to shorts in the system, such as exposed or unsealed wires after splicing, and make sure all connectors are securely locked in place.
Installation of the seals also require careful attention. A folded seal may bind, causing the system to go into an unwanted anti-pinch mode during operation. Use tape to hold the top lip seal of the side rail during installation of the side rail to the canister.
In addition, verify the width of the side rails before beginning installation of the tonneau cover. Wide rails prevent the cover from contacting the limit switches during calibration and may cause a fault. To address concerns with wide rails, refer to the Pick Box Cover Package Installation (Power Tonneau Cover) document in Service Information.
Cover Adjustments
There also are procedures covered in the bulletin that can be performed if the tonneau cover binds or is excessively noisy. These include using the clutch button on the motor to move the cover manually to inspect for any binding (Fig. 17) and applying silicon spray to the drum springs and tracks.
Fig. 17
Power System
If there is a drop below 9 volts in the 12V battery, the tonneau cover will need to be recalibrated. Always recalibrate the cover if the vehicle’s 12V battery is disconnected for service. The cover also should be recalibrated if the motor clutch button has been disengaged.
Also check for power and ground at the X1 connector located at the power tonneau cover control module, including inspecting the 4 wires connected to the main body wire harness under the left-rear wheel well. (Fig. 18)
Fig. 18
For more details, including additional resources that can be found on gmc.com and in Service Information, refer to Bulletin #23-NA-028.
– Thanks to Mark Shearer
