Performance Checking

A/C Cooling Performance, Testing

Test requirements
- Radiator and condenser clean (clean if necessary)
- Ribbed belt OK and correctly tensioned
- All air ducts, covers and seals OK and properly installed
- Air flow through dust and pollen filter not obstructed by dirt
- Heating and A/C unit properly sealed (when fresh air blower is at maximum speed setting, no additional air is drawn in; air delivery is via vents only)
- Vehicle not standing in direct sunlight
- Expansion valve insulation properly installed and not damaged.
- Engine at normal operating temperature
- All instrument panel vents open
- Engine running and A/C control head -E87- set to "AUTO" mode
- Compressor switched on (LED in "ECON" button not lit up)
- Temperature selection "LO"
- A/C clutch -N25- engages compressor
- Coolant fan(s) -V7- run


NOTE:
- On vehicles equipped with A/C pressure switch, -V7- at speed 1
- Various versions of Coolant Fan Control (FC) Module -J293- used in conjunction with high pressure sensor -G65- may be installed as a running change from version with -F129-. If equipped with -G65-, version up to publishing date is where coolant fan(s) -V7- speed 1 are always switched on automatically whenever the A/C clutch -N25- is energized.


- Fresh air blower -V2- run at maximum speed
- Fresh air/recirculated air flap moved to "recirculated air" setting (within 1 minute of starting the engine)
- Air should come out of the instrument panel vents
- Both temperature flaps in "cooling" position


NOTE: If any of the above test requirements is not obtained, check DTC memory and perform output Diagnostic Test Mode (DTM). Output Diagnostic Test Mode (DTM) (Function 03)


Preparatory steps
- Check DTC Memory and eliminate any malfunctions that may be displayed.
- Perform basic setting and check control module coding Basic Setting (Function 04) Scan Tool Connecting and Initial Checks.
- Close front hood and sunroof.
- Measure ambient temperature.
- Close doors and windows.

Testing
- Switch ignition on.
- Select "AUTO" mode on A/C control head -E87- and switch temperature setting to "LO"
- Start engine.
- A/C clutch engaged, compressor runs.
- Press button for recirculated air.
- LED in button lights.
- Increase engine speed to 2000 RPM (timed period begins).
- Measure temperature of air delivered by instrument panel vents.







- Compare measured values with graph.
A - Temperature of air from center instrument panel vents
B - Measured ambient temperature
C - Permissible temperature range for air from vents







After 5 minutes (depending on ambient temperature) the temperature of air from the center instrument panel vents should settle to within tolerance range -C- on the graph.

Identifying malfunctions if specified values are not obtained

Part 1:

Part 2:

Part 3: