Transmission Neutral Service Mode

2021-2022 CT4, CT5, Escalade, Tahoe, Suburban and Yukon models equipped with the 10L60 10-speed automatic transmission (RPO MQA) or 10L80 10-speed automatic transmission (RPO MHS, MQC) feature an internal Electronic Transmission Range Select (ETRS) system (Fig. 15; Tahoe shown) that requires hydraulic pressure to disengage the park mechanism. Here are some tips to follow to place the transmission in Neutral.


Fig. 15


Vehicles that can be Started

In cases where the engine can be started, refer to the Neutral Service Mode document in the appropriate Service Information (for example, Document ID # 5286309). There are different procedures to follow to have the transmission remain in neutral with the engine on or engine off and with the driver remaining in the vehicle or exiting the vehicle.


Vehicles that cannot be Started

In cases where there is an ETRS system fault or a no start condition and the vehicle needs to be moved, the DT-52910 Manual Park Release tool (Fig. 16) can be installed to temporarily shift the vehicle into Neutral when the engine is not running. The manual park release tool is now available through the GM Special Service Tools website at


Fig. 16


To install the tool, refer to Document ID 5620825. (Fig. 17) Ensure the vehicle is on level ground, the parking brake applied, and the wheels are blocked prior to installing the manual park release tool.


Fig. 17


The transmission will be placed in N (Neutral) when the manual park release is pulled. (Fig. 18)

If the manual park release is pulled while the vehicle is on, or if the ignition is turned on while the manual park release is pulled, the Driver Information Center on the instrument cluster will display a message to service the transmission.


Fig. 18


TIP: The latching mechanism in the manual park release lever will release if the vehicle is started and placed in Park. An attempt to override this function or use of an non-approved tool may cause internal damage to the transmission.

In addition to the DT-52910 Manual Park Release tool, wheel dollies or tire skates (Fig. 19) can be used to move the vehicle when there is an ETRS system fault or a no start condition.


Fig. 19


For more information, refer to Bulletin #21-NA-281.


– Thanks to Mark Gordon

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  1. The DT-52910 Manual Park Release tool for RWD vehicles as well as the DT-52909 Manual Park Release tool for FWD vehicles are not essential tools. The tools can be ordered through

  2. DT-52910 essential tool?? Or do we have to order one?

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