Temperature/Mode Control Knobs May Not Rotate, Air Flow Restricted or HVAC Mode Door Gasket or Temperature Door Gasket Foam Comes Off (Replace A/C Evaporator Case/Heater Case Assembly)

Some customers may comment that the heater-ventilation-air conditioning (HVAC) control assembly temperature control knob or the mode control knob may not rotate or the knob(s) may bind. Customers may also comment that the air flow is restricted or that they cannot shut off the air flow completely from one or more of the mode positions.

Important: For ION vehicles equipped with A/C (RPO C60), the component containing the mode and temperature doors is referred to as the A/C evaporator case assembly; for vehicles without A/C (RPO C41), this component is referred to as the heater case assembly.

The foam gaskets located on the air conditioning (A/C) evaporator case or heater case assembly mode or temperature doors may have come loose, which may cause the door(s) to bind. The loose/missing foam gaskets may also allow air to leak past one of the mode doors when that door is closed.

Evaluate vehicle, and if necessary, replace the A/C evaporator case assembly or heater case assembly with a new A/C evaporator case assembly, P/N 15211498, or heater case assembly, P/N 15211557.

1. Verify customer concern. Once customer concern has been verified and it has been determined that the vehicle is within the vehicle identification number (VIN) range as indicated in this bulletin, proceed to next step.

•	If customer concern cannot be duplicated, collect additional information from the customer regarding their concern. Proceed to "Diagnostic Starting Point - Heating, Ventilation and Air Conditioning" in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #874595).

•	If VIN is higher than 4Z211388, proceed to "Diagnostic Starting Point - Heating, Ventilation and Air Conditioning" in the HVAC section of the 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #874595).

2. Prior to removing the HVAC module assembly, disconnect temperature and mode door cables from temperature cam and mode cam. To disconnect the mode and temperature cables, refer to "Mode Cam Replacement" procedure in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #885676).
3. Once the cables are disconnected, manually rotate temperature and mode cams.

•	If cams rotate freely, the issue may be caused by either the cables or the HVAC controller. Diagnose and repair as necessary. Refer to "Symptoms - HVAC Systems - Manual" in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #874586).

•	If the cam(s) are still binding, proceed to the HVAC module removal procedure in Step 4.

4. Remove HVAC module assembly. Refer to "HVAC Module Assembly Replacement" procedure in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #884883).




Important: Only the A/C evaporator case assembly or heater case assembly (upper part of HVAC module) need to be replaced. The blower case (lower part of HVAC module) does NOT need to be replaced.

5. After removing HVAC module from vehicle, inspect for missing or loose gaskets. Refer to illustration above for an example of loose foam.

•	If gaskets are missing or loose on vehicles equipped with A/C (RPO C60), replace A/C evaporator case assembly with new evaporator case assembly, P/N 15211498.

•	If gaskets are missing or loose on vehicles without A/C (RPO C41), replace heater case assembly with new heater case assembly, P/N 15211557.

•	If gaskets are not missing or loose, refer to "Symptoms - HVAC Systems - Manual" in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #874586) for further diagnostic information.

6. Transfer all the necessary components from original A/C evaporator case or heater case to new A/C evaporator case or heater case.
7. Install HVAC module assembly. Refer to "HVAC Module Assembly Replacement" procedure in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #884883).
8. Connect temperature and mode door cables to temperature and mode cams. Refer to "Mode Cam Replacement" procedure in the HVAC section of the 2003 or 2004 Saturn ION Service Manual, Vol. 1 (SI Document ID #885676).
9. Verify that condition has been eliminated.

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System for D2009 (Heater Module Components, Passenger Compartment, Heater/Air Distribution Case -- R & R or replace).