Cooling Fan Inoperative - Suzuki XL7 2007 Service Manual

1F-13 Engine Cooling System:
Component Testing
1. Ignition OFF, disconnect the cooling fan relay.
2. Test for 70-110 ohms of resistance between
terminals 85 and 86.
➢ If the resistance is not within the specified range,
replace the relay.
3. Test for infinite resistance between the following
terminals:
– 30 and 86
– 30 and 87
– 30 and 85
– 85 and 87
➢ If not the specified value, replace the relay.
4. Test for less than 2 ohms of resistance between
terminals 30 and 87A.
➢ If greater than the specified value, replace the
relay.
5. Install a 20A fused jumper wire between relay
terminal 85 and 12 volts. Install a jumper wire
between relay terminal 86 and ground. Test for less
than 2 ohms of resistance between terminals 30 and
87.
➢ If greater than the specified value, replace the
relay.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Engine Coolant Fan Motor Replacement"
• "Relay Replacement (Within an Electrical Center): "
"Relay Replacement (Attached to Wire Harness): "

Cooling Fan Inoperative

Diagnostic Instructions
• Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
• Review "Strategy Based Diagnosis: " for an overview
of the diagnostic approach.
• "Diagnostic Procedure Instructions - Vehicle
Diagnostic Information: " provides an overview of
each diagnostic category.
Circuit/System Description
The engine control module (ECM) commands the fans
ON in either high speed or low speed, depending on
cooling requirements. In low speed, both fans are turned
ON at a reduced speed. High speed has both fans
turned ON at full speed.
In low speed operation, the ECM applies ground to the
coil side of the cooling fan 1 relay. This energizes the coil
and applies voltage directly to the left cooling fan
through the switch side of the low relay. The left fan is
connected in series to the right cooling fan through the
normally closed contacts of the fan 2 relay. The series
circuit operates both fans at low speed.
In high speed operation, the ECM applies a ground to
the coil side of the cooling fan 3 relay, the fan 2 relay,
and the fan 3 relay. When energized, the fan 3 relay
applies voltage directly to the right cooling fan through
the switch side of the relay. Simultaneously, the fan 1
relay and the fan 2 relay provide ignition voltage and a
direct path to ground for the left cooling fan. With both
fans connected in a parallel circuit, each fan receives full
voltage and operates at high speed.
Diagnostic Aids
• The ECM has the capability of providing command to
the fan relays even when a scan tool output control is
being used. Always refer to the fan control command
parameters on the scan tool to know which fans are
being commanded ON by the ECM.
• The following tables illustrate the FAN 1 relay, FAN 2
relay and the FAN 3 relay terminal locations in the
underhood fuse block:
Cooling FAN 1 Relay Terminal Identification
B+ - Switch
B+ - Coil
Front of Vehicle
Cooling FAN 2 Relay Terminal Identification
Voltage from Left Cooling
Fan
—
B+ - Coil
Front of Vehicle
Cooling FAN 3 Relay Terminal Identification
Control
B+ - Switch
Front of Vehicle
Control
Cooling Fan Supply
Voltage
Control
Voltage to Right Cooling
Fan
Ground
Cooling Fan Supply
Voltage
B+ - Coil