Service bulletin 21-033-14

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

NHTSA's summary

FLASH: MIL Illumination For P0730 And Transmission Shift Enhancements This bulletin involves selectively erasing and reprogramming the Transmission Control Module (TCM) with new software. A small number of customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation, the technician may find that Diagnostic Trouble Code (DTC) P0730 Incorrect Gear Ratio is setting erroneously. In addition to correcting the DTC, the following Transmission Control Module (TCM) calibration improvements are now available. These updates are broken down by vehicle line and engine category.WK, WD, JK and LC Vehicles equipped with a 3.6L engine (Sales Code ERB) Hanging in gear during HOT ambient temperature conditions while vehicle is loaded or towing. Delayed downshift during acceleration at speeds above 48 kph. (Taiwan, Japan, and China market only). Delayed downshift when driving at altitudes higher than 2500 feet. Inconsistent shifting when towing or while driving up or down steep hills. Delayed upshift while driving in 4 low Intermittent delayed shift. Delayed engagement when shifting from drive to reverse while in 4 low. (JK Rubicon only) Delayed shift from second gear while towing or driving on steep grades. (JK Rubicon only) Intermittent delayed engagement from reverse to drive. Less than desired shift quality in AutoStick mode. (LC vehicles only) Fuel economy improvements. (LC vehicles only)LC Vehicles equipped with a 5.7L engine (Sales Codes EZH or EZC) Hanging in gear during HOT ambient temperature conditions while vehicle is loaded or towing. Bump sensation felt during deceleration or braking. Fuel economy improvements.LC and WK Vehicles equipped with a 6.4L engine (Sales Codes ESH or ESG) Bump sensation felt during deceleration or braking. (LC only) Inconsistent downshift during Wide Open Throttle (WOT) accelerations at highway speeds (i.e. passing). Transmission enhancements to improve acceleration while in reverse going uphill on steep

The document

• NHTSA's copy of the document (PDF)
• If that address does not open, try this one

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Fuel system, Lighting, Transmission and driveline

Trouble codes named

P0730

Listing a model year does not mean every vehicle of it is concerned: the document says which.

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

• Bulletins for another vehicle
• Report an error on this page
• Report an error by email