Jeep Grand Cherokee 2018 — technical service bulletin
Bulletin 21-009-26 · NHTSA communication 11027640 · issued Jan 10, 2026
Technical service bulletin
communication type
Power Train
component
2018
model years
1
vehicle entries
Official summary
Flash: Transmission Control Module (TCM) Updates *Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):** ● P0979-00 - Shift Solenoid 3 Control Circuit Low. ● P0219-00 - Engine Overspeed Condition. ● P0731-00 - Gear 1 Shift Incorrect Ratio. **Customers may experience the following: ● Shift shudder and shift shock during wide open throttle, high clutch energy shift.** The following software update is also included: ● Improved high RPM in coasting situations for the 1-2 shift This bu
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.