Steering Wheel Controls Inoperative - Suzuki XL7 2007 Service Manual

9O-53 Cellular / Entertainment / Navigation / Audio:

Steering Wheel Controls Inoperative

Diagnostic Fault Information
Perform the "Diagnostic System Check - Vehicle
Diagnostic Information: " prior to using this diagnostic
procedure.
Circuit/System Description
The body control module (BCM) supplies voltage to the
audio steering wheel control multiple momentary contact
switches and monitors the return signal. Each switch is
associated to a set resistance value, when pressed a
specific voltage drop occurs through a series of resistors
unique to that switch. The BCM identifies the selection,
then sends a serial data message that is received by the
component controlled, activating the feature.
Diagnostic Aids
• This diagnostic is for the audio steering wheel
controls.
• Before diagnosis of the steering wheel controls,
ensure the primary controls of the associated
component are functioning properly.
• Review schematic when testing switch resistance
values.
• If a single switch function is inoperative, test the
suspect switch. Refer to component testing.
Reference Information
Schematic Reference
"Steering Wheel Secondary/Configurable Control
Schematics"
Connector End View Reference
• "Data Communication Connector End Views: "
• "Secondary/Configurable Control Connector End
Views"
Description and Operation
"Steering Wheel Controls 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 - Secondary and Configurable
Customer Controls"
• "Scan Tool Data Definitions - Secondary and
Configurable Customer Controls"
Circuit/System Verification
Ignition ON, observe the scan tool SWC Bank 1 status
while pressing and releasing the switches. The reading
should be SW1-SW7 identifying the switch pressed, and
Idle when released.
Circuit/System Testing
NOTE
It is recommended that component testing is
performed before circuit testing when
diagnosing steering wheel controls.
WARNING
!
Refer to "SIR Caution: ".
1. Ignition OFF, disconnect the harness connector at
the right steering wheel control switch.
2. Ignition ON, test for ignition voltage between the
ignition circuit terminal 3 and ground.
➢ If less than specified value, test the ignition circuit
for a short to ground or open/high resistance. If the
circuit tests normal, replace the BCM.
3. Test for the 0 volts between the signal circuit terminal
4 and ground.
➢ If greater than specified value, test the signal circuit
for a short to voltage. If the circuit tests normal,
replace the BCM.
4. Test for ignition voltage between the ignition circuit
terminal 3 and the signal circuit terminal 4.
➢ If less than specified value, test the signal circuit for
an open/high resistance. If the circuit tests normal,
replace the BCM.
5. Ignition OFF, disconnect the C1 harness connector
at the BCM.
6. Test for infinite resistance between the signal circuit
terminal 6 and ground.
➢ If not the specified value, test the signal circuit for a
short to ground.
7. If all circuits test normal, test or replace switch.
Component Testing
WARNING
!
Refer to "SIR Caution: ".
1. Ignition OFF, disconnect the harness connector at
the suspect steering wheel control switch.
2. Test for infinite resistance between the ignition
terminal 3 and the signal terminal 4 with the switch in
the open position.
➢ If less than specified value, replace the switch.
3. Test for less than 5400 ohms of resistance between
the signal terminal 4 and the ignition terminal 3 with
the switch in the closed position.
➢ If greater than the specified value, replace the
steering wheel control switch.