Mazda 2006 MX-5 Service Highlights page 489

On-Board Diagnostic Function
• The on-board diagnostic function is incorporated into the following module:
— PCM
— TCM
— DSC HU/CM (with DSC)
— ABS HU/CM (with ABS)
— Keyless control module
— Steering angle sensor
— Instrument cluster
• This function can narrow down CAN system malfunction locations.
• The on-board diagnostic function consists of the following functions.
— Failure detection function, which detects DTCs malfunctions in CAN system-related parts.
— Memory function, which stores detected.
— Self-malfunction diagnostic function, which indicates system malfunctions using DTCs and warning lights.
• Using the WDS or equivalent, DTCs can be read out and deleted.
• The CAN system has a fail-safe function. When a malfunction occurs in CAN system, the transmission module
sends a warning signal and the receiving module illuminates the warning light.
Block diagram
DSC HU/CM
(WITH DSC)
X
1AM
PCM
1AI
TWISTED PAIR
Failure detection function
• The failure detection function in each CAN system-related module detects malfunctions in input/output signals.
• This function outputs the DTC for the detected malfunction to the DLC-2, and also sends the detected result to
the memory function and fail-safe function.
Fail-safe function
• When the failure detection function determines that there is a malfunction, the fail-safe function illuminates a
warning light to inform the driver of the malfunction.
Memory function
• The memory function stores the DTC for the malfunction of input/output signals for related parts, as determined
by the failure detection function.
Self-malfunction diagnostic function
• The self-malfunction diagnostic function determines that there is a malfunction, and outputs a signal, as a DTC,
to the DLC-2. The DTC can be read out using the WDS or equivalent.
CONTROL SYSTEM
KEYLESS
CONTROL MODULE
ABS HU/CM
(WITH ADVANCED
(WITH ABS)
KEYLESS SYSTEM)
W Z Y 4AA
1G 1C
TCM (AT)
STEERING
ANGLE
SENSOR
(WITH DSC)
4Z E F
1J
1L
F E
DLC-2
INSTRUMENT
CLUSTER
:
CAN_H
:
CAN_L
E5U940ZS5002
09–40–5
09–40