#
ON-BOARD DIAGNOSTIC SYSTEM FUNCTION (DYNAMIC STABILITY CONTROL)

BHE040243000T02

## Malfunction Detection Function

• The malfunction detection function detects malfunctions in the input/output signal system of the DSC HU/CM when the ignition switch is at the ON position.

• When the DSC HU/CM are started up, the following malfunction detections are performed.

  – 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.

## 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 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.

  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

Malfunction location | DTC number | Fail-safe function
--- | --- | ---
Warning light illumination status | Control status
WDS or equivalent Display | ABS warning light | Brake system warning light (when parking brake is released) | DSC indicator light | DSC OFF light | ABS control | EBD Control | TCS control | DSC control
Power supply system | B1318 | Illuminated *1 | Not illuminated | Illuminated *1 | Not illuminated | Control disabled *2 | Control enabled | Control disabled *2 | Control disabled *2
DSC HU/CM system | B1342 | Illuminated | Illuminated | Illuminated | Illuminated | Control disabled | Control disabled | Control disabled | Control disabled
Brake switch signal system | B1484 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
C1953
DSC HU/CM configuration system | B2477 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
DSC OFF switch system | C1093 | Not illuminated | Not illuminated | Illuminated | Illuminated | Control enabled | Control enabled | Control disabled | Control disabled
Pump motor, motor relay systems | C1095 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
C1096
PCM communication system | C1119 | Not illuminated | Not illuminated | Illuminated | Not illuminated | Control enabled | Control enabled | Control disabled | Control disabled
C1134
ABS wheel-speed sensor system | C1145 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
C1155
C1165
C1175
C1233
C1234
C1235
C1236
ABS wheel-speed sensor/ABS sensor rotor systems | C1148 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
C1158
C1168
C1178
ABS wheel-speed sensor (slip monitor) system | C1222 | Illuminated | Illuminated | Illuminated | Not illuminated | Control disabled | Control disabled | Control disabled | Control disabled
Valve relay system | C1186 | Illuminated | Illuminated | Illuminated | Not illuminated | Control disabled | Control disabled | Control disabled | Control disabled
C1266
Solenoid valve system | C1194 | Illuminated | Illuminated | Illuminated | Not illuminated | Control disabled | Control disabled | Control disabled | Control disabled
C1198
C1210
C1214
C1242
C1246
C1250
C1254
C1400
C1410
C1957
C1958
Brake fluid pressure sensor system | C1288 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
C1290
C1440
C1730
C1954
Steering angle sensor system | C1295 | Not illuminated | Not illuminated | Illuminated | Not illuminated | Control enabled | Control enabled | Control disabled | Control disabled
C1306
C1307
C1937
C1938
C1956
C2778
Combined sensor system | C1279 | Not illuminated | Not illuminated | Illuminated | Not illuminated | Control enabled | Control enabled | Control disabled | Control disabled
C1280
C1281
C1282
C1951
C1952
C1959
C2768
Incorrect DSC HU/CM installed | C1805 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled
DSC HU/CM control system | C1994 | Illuminated *3 | Not illuminated | Illuminated *3 | Not illuminated | Control disabled *4 | Control enabled | Control disabled *4 | Control disabled *4
CAN communication system | U1900 | Not illuminated *5 | Not illuminated | Illuminated | Illuminated | Control enabled *6 | Control enabled | Control disabled | Control disabled
U2516 | Illuminated | Not illuminated | Illuminated | Not illuminated | Control disabled | Control enabled | Control disabled | Control disabled

  *1 :
If the ignition voltage returns to normal, the light goes out.
  *2 :
If the ignition voltage returns to normal, control is enabled.
  *3 :
Light goes out if the malfunction is repaired.
  *4 :
Control enabled if the malfunction is repaired.
  *5 :
Illuminates if tire size data cannot be received.
  *6 :
Control is disabled if tire size data cannot be received.