Pinpoint Test U: Reduced Outlet Airflow

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Possible Sources
- Plugged cabin air filter
- Improper A/C system refrigerant charge
- Blower motor control module
NOTE: Before carrying out the following test, diagnose all Heating, Ventilation And Air Conditioning (HVAC) control module and Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTCs).

U1 CHECK THE CABIN AIR FILTER
- Ignition OFF.
- Inspect the cabin air filter for possibly plugged or wet. Refer to the appropriate procedure in the appropriate Climate Control System article.
Is the cabin air filter plugged?

Yes REPLACE or REPAIR as needed.

No GO to U2

U2 CHECK THE BLOWER MOTOR OPERATION
- Ignition ON.
- Using the HVAC controls, select panel mode, set temperature to mid range.
- Operate the blower motor through all speeds.
- Turn off the blower motor.
Does the blower motor operate properly?

Yes GO to U3

No DIAGNOSE the blower motor concern. GO to Pinpoint Test J

U3 CHECK THE AIR CONDITIONING (A/C) SYSTEM FOR PROPER CHARGE

NOTE: Proper Air Conditioning (A/C) system diagnosis on a vehicle's compressor is dependent on correct refrigerant system charge and tested in ambient temperatures above 21.1 deg.C (70 deg.F).
- Carry out the refrigerant system tests. REFER to the appropriate GENERAL PROCEDURES .
Did the system pass the refrigerant system tests?

Yes The system is operating correctly at this time.

No REPAIR the concern found in the refrigerant system tests chart.