Tech Tip: What to do if the dual-zone A/C blows warm on the driver's side

June 5, 2020
After connecting a scan tool and finding no diagnostic trouble codes, the technician called ALLDATA Tech-Assist for some advice on how to make the fix.

Vehicle: 2016 Mitsubishi Outlander Sport, 2WD, L4-2.0L, Automatic Transmission

Mileage: 51,004

Problem: The vehicle owner complained that the air conditioner was not cold enough.

Details: The technician verified that the vehicle was equipped with a dual-zone system. The air was cold coming out of the passenger side vents, but not on the driver’s side. He connected a scan tool and found no diagnostic trouble codes. A quick call to ALLDATA Tech-Assist resulted in some interesting experience-based advice.

It seems that these dual-zone systems will cool less on one side or the other when the refrigerant is low. The Tech-Assist consultant suggested verifying if the refrigerant level was correct. If it was not, he advised to inspect the high-pressure liquid line from the compressor to the top right corner of the condenser for leaks; a problem the consultant had noticed happening more often with these vehicles.

After connecting his A/C gauges, the tech found that the refrigerant level was low. He added dye and checked for leaks. As predicted, there were traces of dye at the right, top of the A/C condenser, which indicated a small leak.

Confirmed Repair: The technician recovered the refrigerant, replaced the A/C condenser, and recharged the system with the correct amount of refrigerant. After the repairs, the A/C cooled equally in both zones.

 Information provided by ALLDATA

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