ON-BOARD DIAGNOSTIC SYSTEM FUNCTION [ABS]

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Malfunction detection function

• The malfunction detection function detects and displays malfunctions in the input/output signal system of the ABS HU/CM when the ignition is switched to ON.

• When the ABS HU/CM is activated, the following malfunction detection is performed.

― The ABS and brake system warning lights illuminate for approx. 3.0 s when the ignition is switched to ON 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 are monitored for malfunction diagnosis. After initial acceleration, the pump motor is operated while the vehicle speed is approx. 10 km/h {6.2 mph} or more to perform malfunction diagnosis again. The input/output signals of each part are then constantly monitored and malfunctions are diagnosed.

Note

• When the fail-safe relay and pump motor operate, each of their sounds can be heard.

• If the above malfunctions are detected, the corresponding lights are illuminated to alert the driver. DTCs can be output through the CAN_H and CAN_L of the DLC-2 using the external tester communication function. 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 has been switched off, even if the malfunctioning signal system has returned to normal.

• Since the ABS 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.

DTC 7-digit code definition

• When related systems or components have failed, the CM stores the DTC of the malfunctioning part in the CM memory, and allows for the retrieval of the store data using scanning tool when necessary. The DTCs are indicated using seven digits. Each digit indicates the following.

am3zzn00003047

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 and EBD as indicated in the fail-safe function table.

Warning

• If EBD control is prohibited, the rear wheels could lock-up before the front wheels. If this occurs, the vehicle could yaw and become unstable. Therefore, always inspect the system immediately if EBD control is prohibited.

Fail-safe Function Malfunction Contents

Malfunction location	DTC No.	Fail-safe function
	DTC No.	Warning light illumination status		Control status
	Mazda Modular Diagnostic System (M-MDS) display	ABS warning light	Brake system warning light (parking brake released)	ABS control	EBD control
ABS HU/CM internal malfunction (LF inlet solenoid)	C0010:01	Illuminated	Illuminated	Control disabled	Control disabled
ABS HU/CM internal malfunction (LF outlet solenoid)	C0011:01
ABS HU/CM internal malfunction (RF inlet solenoid)	C0014:01
ABS HU/CM internal malfunction (RF outlet solenoid)	C0015:01
ABS HU/CM internal malfunction (LR inlet solenoid)	C0018:01
ABS HU/CM internal malfunction (LR outlet solenoid)	C0019:01
ABS HU/CM internal malfunction (RR inlet solenoid)	C001C:01
ABS HU/CM internal malfunction (RR outlet solenoid)	C001D:01
Pump motor, motor relay	C0020:01	Illuminated	-	Control disabled	Control enabled
	C0020:1C
	C0020:71
ABS sensor rotor	C0030:07	Illuminated	-^*1	Control disabled	Control enabled^*2
	C0033:07
	C0036:07
	C0039:07
ABS wheel-speed sensor	C0031:01	Illuminated	-^*1	Control disabled	Control enabled^*2
	C0034:01
	C0037:01
	C003A:01
ABS wheel-speed sensor/ABS sensor rotor	C0031:07	Illuminated	-^*1	Control disabled	Control enabled^*2
	C0034:07
	C0037:07
	C003A:07
Brake switch	C0040:64	-	-	Control enabled	Control enabled
ABS CM (internal malfunction)	C0082:47	Illuminated	Illuminated	Control disabled	Control disabled
	C0082:48
	C0082:49
CAN line	U0001:88	Illuminated	-	Control enabled	Control enabled
	U0100:00	-
	U0155:00	Illuminated
ABS CM configuration	U2100:00	Illuminated	-	Control disabled	Control enabled
ABS CM configuration	U2101:00	Illuminated	-	Control disabled	Control enabled
Power supply system	U3003:08	-	-	Control enabled	Control enabled
	U3003:16	Illuminated	-^*3	Control disabled	Control enabled^*3
	U3003:16	Illuminated	Illuminated^*4	Control disabled	Control disabled^*4
	U3003:17	Illuminated	Illuminated	Control disabled	Control disabled

*1 :Illuminates when two wheels or more have a malfunction.

*2 :Control disabled when two wheels or more have a malfunction.

*3 :Detected if condition of 9.4—10.0 V or less continues for 210 ms or more.

*4 :Detected if condition of 7.55—8.45 V or less continues for 10 ms or more.