Suzuki XL7 2007 Service Manual page 1868

7A-54 Heating, Ventilation and Air Conditioning:
Circuit/System Description
The air temperature actuator is a 5-wire bi-directional
electric motor that incorporate a feedback potentiometer.
Low reference, 5-volt reference, position signal, and 2
control circuits enable the actuators to operate. The
control circuits use either a 0 or 12-volt value to
coordinate the actuator movement. When the actuator is
at rest, both control circuits have a value of 0 volts. In
order to move the actuator, the HVAC control module
grounds one of the control circuits while providing the
other with 12 volts. The HVAC control module reverses
the polarity of the control circuits to move the actuator in
the opposite direction. When the actuator shaft rotates,
the potentiometer's adjustable contact changes the door
position signal between 0-5 volts.
Reference Information
Schematic Reference
"HVAC Schematics"
Connector End View Reference
"HVAC Connector End Views"
Description and Operation
• "Air Delivery Description and Operation"
• "Air Temperature Description and Operation"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
Scan Tool Reference
• "Scan Tool Output Controls - HVAC - Automatic"
• "Scan Tool Data List - HVAC - Automatic"
• "Scan Tool Data Definitions - HVAC - Automatic"
Circuit/System Verification
Ignition ON, operate the applicable actuator using the
HVAC controls. The applicable scan tool parameter
should transition from 7 counts to 250 counts.
Circuit/System Testing
1. Ignition OFF, disconnect the air temperature actuator
harness connector at the air temperature actuator.
2. Ignition OFF, test for less than 1.0 ohm of resistance
between the low reference circuit terminal 1and
ground.
➢ If greater than 1.0 ohm, test the low reference
circuit for an open/high resistance. If the circuit
tests normal, replace the hvac control module.
3. Ignition ON, test for 4.8 to 5.2 volts between the 5 -
volt reference circuit terminal 3 and ground.
➢ If less than 4.8 volts, test the 5 -volt reference
circuit for a short to ground or an open/high
resistance. If the circuit tests normal, replace the
hvac control module.
➢ If greater than 5.2 volts, test the 5-volt reference
circuit for a short to voltage. If the circuit tests
normal, replace the HVAC control module.
4. Install a 3-amp fused jumper wire at the signal circuit
terminal 2, test for greater than 5 volts. Toggle the
jumper wire between the low reference circuit
terminal and the 5-volt reference circuit terminal.
➢ If the position signal parameter is less than 5 volts,
test the signal circuit for a short to voltage, or an
open/high resistance. If the circuit tests normal,
replace the HVAC control module.
5. Ignition ON, after 30 seconds verify that a test lamp
illuminates between control circuit A terminal 4 and
B+.
6. Ignition OFF, verify that a test lamp does not
illuminate between control circuit terminal A terminal
4 and B+.
➢ If the test lamp illuminates, test the control circuit
for a short to ground. If the circuit tests normal
replace the HVAC control module.
7. Ignition ON, after 30 seconds verify that a test lamp
illuminates between control circuit B terminal 5 and
B+.
➢ If the test lamp does not illuminate, test the control
circuit for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the
HVAC control module.
8. Ignition OFF, verify that the test lamp does not
illuminate between control circuit B terminal 5 and
B+.
➢ If the test lamp illuminates, test the control circuit
for a short to ground. If the circuit tests normal
replace the HVAC control module.
9. If all circuits test normal, replace the air temperature
actuator.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Control Module References: " for ECM replacement,
setup, and programming.
• "Air Temperature Actuator Replacement"