Jeep Grand Cherokee 2018 — technical service bulletin
Bulletin 21-048-19 · NHTSA communication 10170413 · issued Dec 21, 2019
Technical service bulletin
communication type
Electrical System
component
2018
model years
1
vehicle entries
Official summary
Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs) have been set: P0979-00 - Shift Solenoid 3 Control Circuit Low. P0219-00 - Engine Overspeed Condition. In addition, the customer may notice the following condition:A harsh shift on coast down 3-2 or 2-1.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.