ON-BOARD DIAGNOSTIC
04–02–2
Block Diagram
End Of Sie
ON-BOARD DIAGNOSTIC SYSTEM FUNCTION (ABS, DYNAMIC STABILITY CONTROL)
CHU040243000S02
Malfunction Detection Function
• The malfunction detection function detects malfunctions in the input/output signal system of the ABS HU/CM
(vehicles with ABS) or DSC HU/CM (vehicles with DSC) when the ignition switch is at the ON position.
• When the ABS HU/CM and DSC HU/CM are started up, the following malfunction detections are performed.
ABS HU/CM
— The ABS and brake system warning lights illuminate for approx. 3 s when the ignition switch is turned to
the ON position to inspect for open circuits in the lights. At the same time, the fail-safe relay is operated,
and the input/output signals of each part is monitored for malfunction diagnosis. After starting to drive, the
first time the vehicle speed is approx. 10 km/h {6.2 mph} or more the pump motor is operated and
malfunction diagnosis is performed again.
DSC HU/CM
— The ABS and brake system warning lights, DSC OFF and DSC indicator lights illuminate for approx. 3 s
when the ignition switch is turned to the ON position to inspect for open circuits in the lights. At the same
time, the fail-safe relay is operated, and the input/output signals of each part is monitored for malfunction
diagnosis. After starting to drive, the first time the vehicle speed is approx. 10 km/h {6.2 mph} or more the
pump motor is operated and malfunction diagnosis is performed again.
• When malfunctions are detected, the corresponding lights are illuminated to alert the driver. Using the external
tester communication function, DTCs can be output through the DLC-2 terminal KLN. At the same time,
malfunction detection results are sent to the memory and fail-safe functions.
DSC
INDICATOR
LIGHT*
*ONLY VEHICLES WITH DSC
DSC OFF
LIGHT*
ABS
WARNING
LIGHT
BRAKE
SYSTEM
WARNING
LIGHT
WDS OR
EQUIVALENT
OUTPUT
DEVICES
INPUT
DEVICES
NORMAL CONTROL AREA
PID/DATA
MONITOR
FUNCTION
MALFUNCTION
DETECTION
FUNCTION
ON-BOARD DIAGNOSTIC FUNCTION
MALFUNCTION
INDICATION
FUNCTION
SERIAL
COMMUNICATION
MEMORY
FUNCTION
FAIL-SAFE
FUNCTION
ACTIVE
COMMAND
FUNCTION
HU
INSPECTION
FUNCTION
DLC-2
CHU0402S001