Suzuki SX4 Service Manual page 1047

DTC No. Trouble Area
Temperature selector
B1520
malfunction
Blower speed selector
B1521
malfunction
Air flow selector
B1522
malfunction
Serial communication
B1551
circuit
HVAC control module
B1552
check sum error
CAN communication
B1553
circuit
B1557 VSS signal failure
B1561 ECT signal failure
Outside air
B1562 temperature signal
failure
Engine type signal
B1570
failure
Combination meter
B1571
spec signal failure
When ignition switch is turned ON
after malfunction is already detected
HVAC control module maintains last
normal value.
HVAC control module maintains last
normal value.
HVAC control module maintains last
normal value.
• HVAC control module maintains last
normal value of outside air
temperature.
4 seconds after, HVAC control
module assuming that outside air
temperature is 20 °C (68 °F).
• HVAC control module maintains last
normal value of engine coolant
temperature.
4 seconds after, HVAC control
module assuming that engine
coolant temperature is 80 °C (176
°F).
• HVAC control module controls
actuators assuming that vehicle
speed is 40 km/h (25 mph).
• HVAC control module controls
actuators assuming that engine type
signal is J20.
• HVAC control module controls
actuators assuming that
combination meter spec signal is
US.
HVAC control module controls actuators assuming that vehicle speed is 40 km/h
(25 mph).
HVAC control module maintains last
normal value of engine coolant
temperature. 4 seconds after, HVAC
control module assuming that engine
coolant temperature is 80 °C (176 °F).
HVAC control module maintains last
normal value of outside air
temperature.
4 seconds after, HVAC control module
assuming that outside air temperature
is 20 °C (68 °F).
HVAC control module controls actuators assuming that engine type signal is J20.
HVAC control module controls actuators assuming that combination meter spec
signal is US.
Air Conditioning System: Automatic Type 7B-53
Fail-Safe Operation
When malfunction is detected during
ignition switch is ON
HVAC control module controls actuators
assuming that setting of temperature
selector is 25 °C (77 °F) position.
HVAC control module controls actuators
assuming that setting of blower speed
selector is low (1st) position.
HVAC control module controls actuators
assuming that setting of air flow selector
is DEF position.
HVAC control module controls actuators
assuming that outside air temperature is
20 °C (68 °F), engine coolant
temperature is 80 °C (176 °F), vehicle
speed is 40 km/h (25 mph), engine type
signal is J20 and combination meter spec
signal is US.
HVAC control module controls actuators
assuming that engine
coolant temperature is 80 °C (176 °F).
HVAC control module controls actuators
assuming that outside air temperature is
20 °C (68 °F).