A/C - Temperature Difference Between Panel Vents
NUMBER: 24-007-02GROUP: Heating & A/C
DATE: Aug. 5, 2002
SUBJECT:
A/C Temperature Differential (Stratification) Between Left and Right Front Panel Outlets
OVERVIEW:
This bulletin involves diagnosing A/C temperature difference (stratification) between the left and right front panel outlets.
MODELS:
2001 - 2002 (RS) Town & Country/Caravan/Voyager
2001 - 2002 (RG) Chrysler Voyager (International Markets)
NOTE:
THIS BULLETIN APPLIES TO RS/RG VEHICLES EQUIPPED WITH DUAL ZONE MANUAL (HAD), 3 ZONE MANUAL (HAG), OR ATC (HAH) CLIMATE CONTROL SYSTEMS
SYMPTOM/CONDITION:
More than 12°F warmer outlet air temperature on the left front panel outlet as compared to the right front panel outlet when the HVAC controls are set to max cold.
DIAGNOSIS:
Set the A/C controls so that the compressor is engaged, the air within the vehicle is being recirculated, the output air is being directed through the panel outlets, the temperature control is in the full cool position, and the front and rear (if equipped with rear A/C) blower motor(s) are operating at their highest speed. Use a temperature probe to measure the front left and right panel outlet temperatures. If the difference between the two panel outlets is greater than 12°F, perform the diagnostic procedure below.
EQUIPMENT REQUIRED
DIAGNOSTIC PROCEDURE:
1. Connect DRBIII(R) and check for A/C related Diagnostic Test Codes (DTC). If DTCs are present, repair them using appropriate body diagnostic manual (Heating & A/C section for manual systems and Automatic Temperature Control section for ATC systems) and clear any fault codes related to A/C.
2. Use DRBIII(R) to perform a Heater - A/C Control Calibration as outlined in the appropriate Service Manual (section 24, Controls - Front).
a. If calibration passes, recheck the A/C panel outlet temperature stratification.
b. If the calibration fails: Use the DRBIII(R) for further diagnosis of the DTC's in the appropriate body diagnostic manual (Heating & A/C Diagnostic section) and correct the problem. After calibration is successful, check the A/C panel outlet stratification.
3. Use the DRBIII(R) to perform an A/C Cool Down Test as outlined in the appropriate service manual (section 24, Diagnosis and testing).
a. If the cool down test fails, proceed to A/C Performance Test and verify performance against the temperature and pressure chart in the service manual (Section 24, Diagnosis and Testing). Add refrigerant if necessary and check the A/C panel outlet stratification.
4. Perform diagnosis and testing of expansion valve as described in the appropriate service manual (section 24, Plumbing - Front, Expansion Valve).
a. If the expansion valve fails the test - replace the expansion valve as described in the service manual and proceed to step 5 of this procedure.
b. If the expansion valve passes, review the warranty history for previous compressor failures. If a compressor has previously failed and the expansion valve and/or receiver/drier was not replaced at that time, replace both the expansion valve and receiver/drier.
5. Compare A/C system pressures to the A/C performance chart in the appropriate service manual and recheck for panel outlet stratification.
6. If greater than 12°F stratification exist, replace the evaporator and receiver/drier following procedures in the appropriate service manual (section 24, Plumbing - Front, Evaporator and Receiver/Drier).
POLICY:
Information only.