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A/C - Not Cooling/Poor Performance

NUMBER: 24-007-08 REV. A

GROUP: Heating & Air Conditioning

DATE: October 29, 2008

THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 24-007-08, DATED AUGUST 9, 2008. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS** AND INCLUDE AN ADDITIONAL MODEL YEAR.

StarSCAN(R) SOFTWARE LEVEL MUST BE AT RELEASE 9.030R HIGHER.

StarMOBILE(R) DESKTOP CLIENT MAY ALSO BE USED TO PERFORM THIS PROCEDURE.

SUBJECT:

FLASH: ATC/MTC Poor Performance / Vehicle Not Cooling Enough and/or A/C System Recovery and Recharge

OVERVIEW:
This bulletin involves reprogramming the Automatic Temperature Control Module (ATC) or Manual Temperature Control Module (MTC) -AND/OR- performing an A/C system recovery and recharge with a revised refrigerant level. **2007 Model Year vehicles require a MTC module replacement.**

MODELS:

**2007** - 2008 (KA) Nitro

2008 (KK) Liberty

SYMPTOM/CONDITION:

Some customers may complain that A/C performance is poor and that the A/C is not cooling enough or fails to keep the passenger compartment cool. This update will provide customers with improved A/C performance.

DIAGNOSIS:

1. **Is the vehicle a 2007 model year vehicle?

a. Yes >> Replace the Temperature Control Module with PN 55111884AF. Follow the procedures in TechCONNECT > 24 - Heating & Air Conditioning > Controls > Control, A/C and Heater > Removal/Installation. Door calibration will be performed automatically once the new control module detects key on.

b. No >> Proceed to Step # 2.**

2. **Is the vehicle build date before May 30, 2008?

a. Yes >> Perform the Flash Repair Procedure and A/C system recovery and recharge.

b. No >> For vehicles built between May 30, 2008 and before July 2, 2008, perform Step 7 of the Repair Procedure.**





PARTS REQUIRED:





SPECIAL TOOLS / EQUIPMENT REQUIRED:

REPAIR PROCEDURE - USING THE INTERNET TO RETRIEVE THE FLASH FILE:

NOTE:
When performing this Repair Procedure, the software release level in the StarSCAN(R); must be programmed with 9.03 level software or higher. The software release level is visible in the blue header at the top of the StarSCAN(R) screen.

NOTE:
The StarSCAN(R) diagnostic scan tool fully supports Internet connectivity. However, to take advantage of this feature you must first configure the StarSCAN(R) for your dealership's network. Make sure the StarSCAN(R) is configured to the dealership's network before proceeding. For instruction on setting up your StarSCAN(R) for the dealer's network refer to either:

"DealerCONNECT > Service > StarSCAN(R) and StarMOBILE(R) tools > Online Documentation", or refer to the StarSCAN(R) Quick Start Networking Guide. The StarSCAN(R) Quick Start Networking Guide is also available on the website under the "Download Center".

NOTE:
If this flash process is interrupted/aborted, the flash should be restarted.

NOTE:
The repair Procedure (HVAC Control Flash) can be performed using the StarSCAN and StarMOBILE Standalone and Desktop.

1. Install a battery charger and verify that the charging rate provides approximately 13.5 volts. Set the battery charger to continuous charge. Do not allow the charger to time out during the flash process. Remove the charger from the battery when the flash process is complete.

2. Connect the CH9410 StarSCAN(R) ethernet cable to the StarSCAN(R) and the dealer's network drop.

3. Connect the CH9404D StarSCAN(R) vehicle cable to the StarSCAN(R) and the vehicle.

4. Power ON the StarSCAN(R).

5. Turn the ignition switch on.

6. Retrieve the old HVAC part number. Using the StarSCAN(R) at the "Home" screen:

a. Select "ECU View"

b. Touch the screen to highlight the HVAC in the list of modules.

c. Select "More Options"

d. Select "ECU Flash"

e. Record the part number at the top of the "Flash HVAC" screen for later reference.

f. Select "Browse for New File". Follow the on screen instructions.

g. Select "Download to Scantool".

h. Select "Close" after the download is complete, then select "Back".

i. Highlight the listed calibration.

j. Select "Update Controller". Follow on screen instructions.

k. When the update is complete, select "OK".

l. Verify the part number at the top of the "Flash HVAC" screen has updated to the new part number.

7. Perform an A/C system recovery and recharge following the procedures outlined in DealerCONNECT >> Heating and Air Conditioning >> Standard Procedures >> Follow all CAUTIONS and WARNINGS. **A/C systems on these vehicles were originally charged with 20 ounces of refrigerant. By performing a system recovery and recharge with 18 ounces of refrigerant, improved A/C performance can be achieved.**

NOTE:
Due to the HVAC programming procedure, a DTC may be set in other modules (TCM, BCM, MIC, SKREEM, etc.) within the vehicle, if so equipped. Some DTC's may cause the MIL to illuminate. From the "Home" screen select "System View". Then select "All DTCs". Press "Clear All Stored DTCs" if there are any DTCs shown on the list.

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.