Suzuki XL7 2007 Service Manual page 1852

7A-38 Heating, Ventilation and Air Conditioning:
Step
Inspect the cooling system for leaks. Refer to "Loss of
9 Coolant: ".
Is a leak present?
Inspect for coolant leaking inside the vehicle or for a film build-
10 up on the windshield.
Is the condition present?
Replace the heater core. Refer to "Heater Core Replacement".
11
Is the repair complete?
12 Does the odor have an oily smell?
1. Inspect the engine compartment for any leaks. Refer to the
following procedures:
– "Oil Leak Diagnosis: "
13
– "Fluid Leak Diagnosis: "
2. Repair any oil leaks.
Is the repair complete?
A musty odor can be caused by mold or mildew build-up on
the evaporator or the heater core or inside of the HVAC
14
module. Refer to "Odor Correction".
Is the action complete?
Operate the system in order to verify the repair.
15
Did you find and correct the condition?
Air Conditioning Compressor Malfunction
Diagnostic Instructions
• Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
• "Strategy Based Diagnosis: "
• "Diagnostic Procedure Instructions - Vehicle
Diagnostic Information: "
Diagnostic Fault Information
Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
Circuit/System Description
When the A/C switch is pressed, the HVAC control
module grounds the A/C request signal circuit. The body
control module (BCM) receives the ground input and
sends a GMLAN message to the engine control module
(ECM) for an A/C request. This input will request the
ECM to ground the A/C compressor clutch relay control
circuit, which will switch the A/C CLUTCH relay. With the
relay contacts closed, battery voltage is supplied to the
A/C compressor clutch assembly.
Action
Diagnostic Aids
The following conditions must be met in order for the
ECM to turn on the compressor clutch:
• Battery voltage is between 9-16 volts.
• Engine coolant temperature (ECT) is less than 123°C
• Engine speed is less than 4760 RPM.
• Engine speed is more than 600 RPM.
• A/C high side pressure is between 2929-269 kPa
• Throttle position is less than 100 percent.
• Evaporator temperature is greater than 0°C (32°F)
• ECM does not detect excessive torque load
• ECM does not detect insufficient idle quality.
Reference Information
Schematic Reference
"HVAC Schematics"
Connector End View Reference
"HVAC Connector End Views"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
• "Wiring Repairs: "
Scan Tool Reference
• "Scan Tool Data List - HVAC - Automatic"
• "Scan Tool Data Definitions - HVAC - Automatic"
• "Scan Tool Output Controls - HVAC - Automatic"
Yes
Go to Step 10
Go to Step 11
Go to Step 15
Go to Step 13
Go to Step 15
Go to Step 15
System OK
(253°F).
(425-39 psi).
Connections: "
No
Go to Step 12
Go to Step 15
—
Go to Step 15
—
—
Go to Step 2