Transmission Neutral Service Mode on 10-Speed Automatic Transmissions

The 10L80 10-speed automatic transmission (RPO MHS, MQC) available on the new 2022 Silverado 1500 and Sierra 1500 features the Electronic Transmission Range Select (ETRS) system, which electronically shifts the transmission into the gear selected. (Fig. 15) The ETRS system does not have a mechanical linkage to the transmission.

In addition to the new trucks, ETRS is included on 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).

Fig. 15

The ETRS system requires hydraulic pressure to disengage the park mechanism. Here are some tips to follow to place the transmission in Neutral, depending on the state of vehicle power.

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 gmtoolsandequipment.com.

Fig. 16

To install the tool, refer to Document ID 5620825. The transmission will be placed in N (Neutral) when the manual park release is pulled. (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

If the manual park release (Fig. 18) 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 and David MacGillis

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2 Comments

  1. James McPherson says:

    This is without a doubt one of the stupidest things I have ever seen GM produce. The arrogance of building a vehicle that can’t be moved in neutral when the engine won’t start is absolutely baffling. When the stop/start system fails to restart the vehicle at a red light the driver has to block traffic for an hour while waiting for a tow truck? And good luck pushing/pulling a dead vehicle into a shop on wheel dollies with tiny little wheels on an icy/snow covered parking lot. I’m supposed to go outside when it’s -30 celsius, jack up the vehicle in an icy parking lot so I can install bolts into dirt filled open bolt holes? This is disgusting and you should be ashamed of yourselves for not building a redundancy into the vehicle. For shame GM, for shame.

  2. chad roberts says:

    Can’t i just turn the manual shift shaft with a wrench like all other trans?

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