Fix for a P182E code on a GM vehicle

The P182E code on a GM vehicle is usually caused by a bad internal mode switch

GM has issued a service bulletin for a P182E code

GM has issued a technical service bulletin #17-NA-084 to address a Check engine light on and a P182E code on the vehicles listed below. In addition to the check engine light and P182E trouble code, you may also notice that there is no no PRNDL display on your instrument cluster. You may also notice hard shifting

A P182E code is defined as: Internal Mode Switch Indicates Invalid Range set as Active

The internal mode switch is moved by the shift cable and tells the transmission control module which gear you’ve chosen.

Vehicles affected by technical service bulletin #17-NA-084

2009-17 Buick Enclave
2010-17 Buick LaCrosse
2012-17 Buick Regal
2010-16 Cadillac SRX
2012-18 Cadillac XTS
2009-17 Chevrolet Equinox, Malibu, Traverse
2009-18 Chevrolet Impala
2009-18 GMC Acadia
2010-17 GMC Terrain
2009 Pontiac G6, Torrent
2009-10 Saturn AURA, OUTLOOK, VUE

How to diagnose and fix a P182E code

You’ll need scan tool with live data or a digital multimeter to diagnose the internal mode switch.

Start by verifying that the shift cable is properly adjusted. The shift cable adjustment procedure is different for each vehicle. You’ll need a shop manual to perform this step. Do not skip it or you could wind up the same problem after replacing the internal mode switch.

The shop manual also includes the full range of voltage readings you should see for each gear. However, if you have a scan tool with live data, you won’t need the chart. Simply move the shifter and see if the internal mode switch reports the correct gear selection.

Replace the internal mode switch

The internal mode switch is located inside the transmission. To replace it you’ll have to remove the shift cable and the lower control valve body from the side of the transmission. This will involve replacing transmission fluid, so you’ll need the refilling tool and the proper fluid before proceeding with the repair.

Internal mode switch

After replacing the internal mode switch, adjust the shift cable and clear the trouble codes.

©, 2019 Rick Muscoplat