Ja, es geht darum, den 5. Gang "freizuschalten".
Hier die Info von WJJeeps.com:
Part I - Grand Cherokee Technical Service Bulletin Index
WJ Series: 1999-2004 Model Years
1802501 - 45RFE AND 545RFE SHIFT QUALITY ENHANCEMENTS FOR THE 2-3, 4-5, AND 5-4 SHIFTS / ADDITION OF 5TH GEAR RATIO
Date: 10/15/01 (supersedes 210900 dated 09/15/00)
Model year(s): 1999-2001
Description: This bulletin involves selectively erasing and reprogramming the Transmission Control Module (TCM) with new software: ’99-’01 WJ (PN 05019701AC Ver 9.3 ), and requires reprogramming of the Powertrain Control Module (PCM) for the 1999 and 2000 Grand Cherokees (with calibration 99Cal20 (1999) or 00Cal17 (2000).
NOTE: THE 2001 GRAND CHEROKEE DOES NOT REQUIRE REPROGRAMMING OF THE PCM AS IT IS ALREADY AT THE CORRECT CALIBRATION LEVEL.
NOTE: WHENEVER A PCM OR TCM IS REPLACED OR REPROGRAMMED, THE SOFTWARE OF THE PCM MUST BE VERIFIED AS HAVING THE LATEST REVISION LEVEL.
Details: Some vehicles may exhibit one or more of the following performance conditions:
1. A harsh 2-3 upshift causing a powertrain clunk or shudder when accelerating.
2. A harsh 4-5 upshift (’01 Grand Cherokee only).
3. A harsh 5-4 downshift (’01 Grand Cherokee only).
NOTE: THIS REVISION TO THE TCM SOFTWARE ADDRESSES THE ABOVE SHIFT QUALITY CONDITIONS FOR ALL VEHICLES AND ADDS A FINAL GEAR RATIO TO THE 1999 AND 2000 MY GRAND CHEROKEE TRANSMISSION ONLY. (2001 MY GRAND CHEROKEES ALREADY HAVE THIS UPGRADE.)
NOTE: Owners of 1999-2000 models who want to verify if they have the 5th gear ratio or not can check their engine RPM at 70 mph. Vehicles without the upgrade will have an RPM of around 2400-2500 while those having the new 5th gear ratio will be very close to 2000 RPM.
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