Control; Memory Function; Fail-Safe Function - Mazda RX-8 2004 Service Highlights

Memory Function

• The memory function stores DTCs of malfunctions in input/output signal systems. With this function, once a
DTC is stored it is not cleared after the ignition switch has been turned off (LOCK position), even if the
malfunctioning signal system has returned to normal.
• Since the ABS HU/CM or DSC HU/CM has a built-in non-volatile memory, DTCs are not cleared even if the
battery is removed. Therefore, it is necessary to clear the memory after performing repairs. Refer to the
Workshop Manual for the DTC clearing procedure.

Fail-safe Function

• When the malfunction detection function determines a malfunction, each light illuminates to advise the driver.
At this time, the fail-safe function controls the ABS, EBD, TCS* and DSC* as shown in the fail-safe function
table.
*: Only vehicles with DSC
Warning
• If EBD control is suspended the rear wheels could lock-up before the front wheels. If this occurs,
the vehicle could swerve and become unstable. Therefore always inspect the system immediately
if EBD control is suspended.
Fail-safe Function Malfunction Contents (Vehicles With ABS)
DTC number
Malfunction
WDS or
location
equivalent
display
Power supply system B1318
ABS HU/CM system B1342
C1145
C1148
C1155
C1158
ABS wheel-speed
sensor system
C1165
C1168
C1175
C1178
C1233
ABS wheel-speed
C1234
sensor/ABS sensor
C1235
rotor systems
C1236
C1194
C1198
C1210
C1214
Solenoid valve
system
C1242
C1246
C1250
C1254
ABS HU/CM internal
C1140
pump system
C1510
Solenoid valve, pump
C1511
motor, ABS wheel
speed sensor/ABS
C1512
sensor rotor systems
C1513
C1186
Fail-safe relay
system
C1266
ON-BOARD DIAGNOSTIC
Warning light illumination status
Brake system
warning light (when
ABS warning light
parking brake is
released)
*1
Illuminated Illuminated
Illuminated Illuminated
Illuminated
Not illuminated
Illuminated
Not illuminated
Illuminated
Illuminated
Illuminated Not illuminated
Illuminated
Not illuminated
Illuminated
Illuminated
Not illuminated
Fail-safe function
Control status
ABS control
*1
Control enabled
Control disabled
*2
Control disabled
*4
Control disabled
*6
Control disabled
Control disabled
*2
Control disabled
Control disabled
04–02
EBD control
Control enabled
Control disabled

Control

*3
enabled
Control
*5
enabled
Control
*7
disabled
Control enabled
Control
*3
enabled
Control disabled
Control enabled
04–02–3