Suzuki XL7 2007 Service Manual page 2581

Circuit/System Description
When you depress the rear defogger button, voltage is
supplied to the DEFOG relay coil and the HVAC control
module also illuminates the rear window defogger
indicator. Battery positive voltage is supplied at all times
to the DEFOG relay switched input and the DEFOG
relay coil is always grounded. This allows battery
positive voltage from the relay switched input through
the switch contacts and out the relay switched output to
the rear window defogger. Ground for the rear defogger
grid is provided by G401.
When you start the engine and press the rear defogger
switch for the first time, the defogger cycle lasts for 15
minutes. Further operation results in 7.5 minute
defogger cycles. The defogger cycle resets to 15
minutes when you cycle the ignition to the OFF position
and then to the ON position.
Reference Information
Schematic Reference
"Defogger Schematics"
Connector End View Reference
"Window Systems Connector End Views"
Description and Operation
"Rear Window Defogger Description and Operation"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
Scan Tool Reference
• "Scan Tool Data List - Fixed and Moveable Windows"
• "Scan Tool Data Definitions - Fixed and Moveable
Windows"
• "Scan Tool Output Controls - Fixed and Moveable
Windows"
Circuit/System Verification
1. Ignition ON, observe the operation of the Rear
Defogger Grid while pressing the Rear Defogger
Switch. The Rear Defogger Grid should ACTIVATE
and DEACTIVATE when changing between
commanded states.
2. Command the rear window defogger indicator ON
and OFF with the scan tool. The rear window
defogger indicator should turn ON and OFF when
changing between the commanded states.
➢ If the Defogger Indicator does not illuminate,
replace the HVAC control module.
Glass / Windows / Mirrors:
Circuit/System Testing
1. Ignition OFF, disconnect the REAR DEFOG relay.
2. Ignition OFF, test for less than 1.0 ohm of resistance
between the relay coil ground circuit terminal 25 and
ground.
➢ If greater than the specified range, test for an open/
high resistance.
3. Ignition ON, verify that a test lamp does not
illuminate between the relay controlled output circuit
terminal 46 and ground.
➢ If the test lamp illuminates, test the control circuit
for a short to voltage.
4. Verify that a test lamp illuminates between the relay
switch B+ circuit terminal 43 and ground.
➢ If the test lamp does not illuminate, test the B+
circuit for a short to ground or an open/high
resistance. If the circuit tests normal and the RR
DEFOG circuit fuse is open, test the relay
controlled output circuit terminal 46 for a short to
ground
5. Ignition OFF, disconnect the harness connectors C1
and C2 at the Rear Defogger Grid.
6. Ignition OFF, test for less than 1.0 ohm of resistance
between the Rear Defogger Grid ground circuit
terminal 1 and ground.
➢ If greater than the specified range, test the ground
circuit for an open/high resistance.
7. Connect the harness connectors at the Rear
Defogger Grid.
8. Ignition ON, connect a 30-A fused jumper wire
between the relay switch B+ circuit terminal 43 and
the relay controlled output circuit terminal 46. Verify
the Rear Defogger Grid is activated.
➢ If the Rear Defogger Grid does not activate, test the
control circuit for an open/high resistance. If the
circuit tests normal, test or replace the Rear
Defogger Grid.
9. Connect a test lamp between the relay coil control
circuit terminal 39 and the relay coil ground circuit
terminal 25.
10. Command the Rear Defogger Grid ON and OFF by
pressing the Rear Defogger Switch. The test lamp
should turn ON and OFF when changing between
the commanded states.
➢ If the test lamp is always ON, test the control circuit
for a short to voltage. If the circuit tests normal,
replace the HVAC Control Module.
➢ If the test lamp is always OFF, test the control
circuit for a short to ground or an open/high
resistance. If the circuit tests normal, replace the
HVAC Control Module.
11. If all circuits test normal, test or replace the DEFOG
Relay.
9E-33