A/T Controls - MIL ON/DTC's Set/Lack Of Performance
NUMBER: 18-020-11GROUP: Vehicle Performance
DATE: April 19, 2011
HELP USING THE wiTECH DIAGNOSTIC APPLICATION FOR FLASHING AN ECU IS AVAILABLE BY SELECTING "HELP" THEN "HELP CONTENTS" AT THE TOP OF THE wiTECH DIAGNOSTIC APPLICATION WINDOW.
THE wiTECH SOFTWARE LEVEL MUST BE AT RELEASE 11.03 OR HIGHER TO PERFORM THIS PROCEDURE.
SUBJECT:
Flash: MIL Illumination And Driveability/Transmission Improvements
OVERVIEW:
This bulletin involves flash reprogramming the Transmission Control Module (1CM) with new software.
MODELS:
2011 (JK) Wrangler (International Only)
2011 (KA) Nitro
2011 (KK) Liberty (International Only)
2011 (LC) Challenger
NOTE:
This Service Bulletin applies to vehicles equipped with a NAG1 transmission (Sales Code DGJ) built before February 1, 2011 (MDH 0201XX).
SYMPTOM/CONDITION:
Some customers may notice any of the following;
MIL Illumination
Upon further investigation the Technician may find that the following Diagnostic Trouble Codes (DTC) have been set:
a. P0730 - Incorrect Gear Ratio(All Body). See Item "C" below for explanation.
b. P0219 - Engine Overspeed (All Body).
Driveability Improvements:
a. At a light throttle tip in (2 to 6%) the RPM may oscillate slightly (+/-200 rpm). If the throttle tip in is increased then the issue is not present (All Body).
b. Lacks Performance. Some driving conditions can produce circumstances where some customers may perceive more pedal effort is required to get the Powertrain to accelerate the vehicle as desired. The PCM calibration for pedal vs. torque relationship was changed to allow for more torque delivery at less pedal effort/travel. In accordance with this PCM calibration change, the 1CM was re-calibrated to provide optimal performance and fuel economy. The combined PCM and TCM software improvements will translate into a feeling of improved performance to the driver (All Body).
c. Customer describes a temporary "Loss of Power" event due to transmission going to Neutral during a heavy throttle 4-3 downshift. This may happen when driving at moderate speed, 35 to 70 MPH (56 to 112 KPH) when the driver accelerates with pedal input from 40-100% triggering a 4-3 downshift. The may set the P0730 - Incorrect Gear Ratio DTC along with the MIL light ON and cause a Neutral condition within the transmission. This will typically be described as a "Loss of Power" complaint. The MIL for the P0730 will clear after 3 consecutive ignition cycles without setting another P0730 DTC. The P0730 DTC will remain stored in the 1CM for 40 consecutive "good" ignition cycles and then be cleared. To correct this condition the TCM pressure control and torque management were re-calibrated improve the 4-3 downshift control during these conditions (All Body).
Transmission Improvements:
a. Lack of performance feeling during low vehicle speed turning or cornering maneuvers. To correct this condition a new TCM feature was developed to detect when the vehicle is in a turn and will then not perform an upshift (All Body).
b. Harsh 3-4-3 change mind shift. This happens when driving at moderate speed of 30 to 50 mph (48 to 80 kmh) when the driver reduces accelerator pedal input to 5-10%. The TCM then schedules a 3-4 upshift. When the driver accelerates rapidly, pedal input from 40-100% this will CANCEL the 3-4 upshift and trigger a "change mind" shift and revert back to 3rd gear. The TCM "change mind" pressure control and torque management were re-calibrated to smooth the shift control during this maneuver (All Body).
c. Noticeable higher engine RPM during low speed driving. This condition will be noticed during parking lot or city traffic low speed driving. The TCM logic was refined to keep the upshift inhibit more linear vs. vehicle speed (All Body).
d. Transmission not shifting into next higher gear while driving up or down hills or while driving at high altitude. The TCM logic has been changed to compensate for these two conditions. (LC 3.6L Only).
e. Down shift bumps while driving between 35 to 70 MPH (56 to 112 KPH) and the driver performs a wide open throttle (WOT). The TCM logic was optimized to smooth out the 5-2 and 4-2 downshifts during a WOT condition (LC 3.6L Only).
f. High RPM when transmission is in the low range mode. This condition will happen when the driver performs a WOT from a stop. The TCM logic was optimized to prevent a delayed upshift while in low range and a WOT maneuver is performed (JK 2.8L Only).
DIAGNOSIS:
Using a Scan Tool (wiTECH(TM)) with the appropriate Diagnostic Procedures available in TechCONNECT, verify no DTC's are set. If DTC's are present other then the ones listed above record them on the repair order and repair as necessary before proceeding further with this bulletin.
If the customer describes the symptom or if the technician finds the DTC, perform the Repair Procedure.
PARTS REQUIRED:
REPAIR PROCEDURE:
NOTE:
Install a battery charger to ensure battery voltage does not drop below 13.2 volts. Do not allow the charging voltage to climb above 13.5 volts during the flash process.
NOTE:
If this flash process is interrupted/aborted, the flash should be restarted.
1. Reprogram the TCM with the latest software. Help using the wiTECH diagnostic application for flashing an ECU is available by selecting "Help then "Help Contents at the top of the wiTECH diagnostic application window. After TCM reprogramming, the following must be performed:
a. Clear any DTC's that may have been set in other modules due to reprogramming. The wiTECH application will automatically present all DTCs after the flash and allow the tech to clear them.
2. Type the necessary information on the "Authorized Modification Label" and attach it near the VECI label.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE:
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.