ON-BOARD DIAGNOSTIC FUNCTION [BODY CONTROL MODULE (BCM)]

• The on-board diagnostic system consists of a malfunction detection system that detects abnormalities in input/output signals, a data monitor function that reads out specified input/output signals.

• The data link connector 2 (DLC-2), which groups together all the connectors used for malfunction diagnosis and detecting/repair into a single location, has been adopted, thereby improving serviceability. Diagnosis is performed by connecting the Mazda Modular Diagnostic System (M-MDS) to the DLC-2.

• In addition to DTC read-out, the Mazda Modular Diagnostic System (M-MDS) is used to clear DTCs using the display screen of the diagnostic tester, and to access the PID/data monitor function, providing enhanced malfunction diagnosis and improved serviceability.

• The malfunction detection function detects malfunctions in the input/output signal system of the BCM.

DTC No.	Description	Detection condition
B1317	• BCM power supply voltage from the battery is 16 V or more.	BCM power supply voltage high input
B1318	• BCM power supply voltage from the battery is less than 9 V.	BCM power supply voltage low input
B1322	• Short to ground in front door switch (driver-side) circuit with the front door (driver-side) closed (front door switch (driver-side) off).	Front door switch (driver-side) circuit malfunction
B1330	• Short to ground in front door switch (passenger-side) circuit with the front door (passenger-side) closed (front door switch (passenger-side) off).	Front door switch (passenger-side) circuit malfunction
B1342	• BCM detects the internal ECU malfunction.	BCM internal ECU malfunction
B1502	• Short to ground in turn switch (LH) circuit with the turn switch off.	Turn switch (LH) circuit malfunction
B1506	• Short to ground in turn switch (RH) circuit with the turn switch off.	Turn switch (RH) circuit malfunction
B1520	• Open circuit in bonnet latch switch circuit with the bonnet closed (bonnet latch switch on).	Bonnet latch switch circuit malfunction
B1566	• Short to ground in rear door switch (LH) or (RH) circuit with the rear doors closed (rear door switches off).	Rear door switch (LH)/(RH) circuit malfunction
B1614	• Short to ground in rear wiper INT switch circuit with the rear wiper switch off.	Rear wiper INT switch circuit malfunction
B1873	• Short to ground in hazard warning switch circuit with the hazard warning switch off.	Hazard warning switch circuit malfunction
B2218	• Door lock switch (driver-side) or (passenger-side) circuit voltage is less than 3.75 V with the door lock switches off.	Door lock switch (driver-side)/(passenger-side) circuit malfunction
B2574	• Short to ground in front door lock-link switch (driver-side) lock-side circuit with the front door lock-link switch (driver-side) unlocked.	Front door lock-link switch (driver-side) lock-side circuit malfunction
B257C	• Open circuit in front door lock-link switch (passenger-side), rear door lock-link switch (LH) or (RH) circuit with the door lock-link switches unlocked.	Front door lock-link switch (passenger-side)/rear door lock-link switch (LH)/(RH) circuit malfunction
B2721	• Short to ground in liftgate latch switch circuit with the liftgate closed (liftgate latch switch off).	Liftgate latch switch circuit malfunction
B2982	• Open circuit in parking brake switch circuit with the parking brake lever pulled (parking brake switch on).	Parking brake switch circuit malfunction
C1189	• Short to ground in brake fluid level sensor circuit with the brake fluid level on the upper side of the MIN.	Brake fluid level sensor circuit malfunction
C1295	• BCM detects the steering angle sensor internal abnormality (signal overflow).	Steering angle sensor internal malfunction
C1307	• BCM detects the steering angle sensor internal abnormality (signal jump).	Steering angle sensor encoder ring defective
C1441	• Open circuit in steering angle sensor A signal circuit.	Steering angle sensor A signal circuit malfunction
C1442	• Open circuit in steering angle sensor B signal circuit.	Steering angle sensor B signal circuit malfunction
C1443	• Short to ground in steering angle sensor A signal circuit.	Steering angle sensor A signal circuit malfunction
C1444	• Short to ground in steering angle sensor B signal circuit.	Steering angle sensor B signal circuit malfunction
C144A	• Short to ground in steering angle sensor C signal circuit.	Steering angle sensor C signal circuit malfunction
C144B	• Short to ground in steering angle sensor Z signal circuit.	Steering angle sensor Z signal circuit malfunction
C144C	• Open circuit in steering angle sensor C signal circuit.	Steering angle sensor C signal circuit malfunction
C144D	• Open circuit in steering angle sensor Z signal circuit.	Steering angle sensor Z signal circuit malfunction
C1937	• BCM lost the steering angle initialization position.	Steering angle sensor offset failure
U0073	• BCM detects a CAN bus communication line (HS-CAN) malfunction.	Module communication error (HS-CAN)
U0100	• BCM cannot receive the CAN signal from the PCM for 5 s or more.	Communication error with PCM
U0101	• BCM cannot receive the CAN signal from the TCM for 5 s or more.	Communication error with TCM
U0121	• BCM cannot receive the CAN signal from the DSC/RSC HU/CM for 5 s or more.	Communication error with DSC/RSC HU/CM
U0401	• BCM receives the invalid data from the PCM for 5 s or more.	Error signal from PCM

DTC No.

Description

Detection condition

B1317

• BCM power supply voltage from the battery is 16 V or more.

BCM power supply voltage high input

B1318

• BCM power supply voltage from the battery is less than 9 V.

BCM power supply voltage low input

B1322

• Short to ground in front door switch (driver-side) circuit with the front door (driver-side) closed (front door switch (driver-side) off).

Front door switch (driver-side) circuit malfunction

B1330

• Short to ground in front door switch (passenger-side) circuit with the front door (passenger-side) closed (front door switch (passenger-side) off).

Front door switch (passenger-side) circuit malfunction

B1342

• BCM detects the internal ECU malfunction.

BCM internal ECU malfunction

B1502

• Short to ground in turn switch (LH) circuit with the turn switch off.

Turn switch (LH) circuit malfunction

B1506

• Short to ground in turn switch (RH) circuit with the turn switch off.

Turn switch (RH) circuit malfunction

B1520

• Open circuit in bonnet latch switch circuit with the bonnet closed (bonnet latch switch on).

Bonnet latch switch circuit malfunction

B1566

• Short to ground in rear door switch (LH) or (RH) circuit with the rear doors closed (rear door switches off).

Rear door switch (LH)/(RH) circuit malfunction

B1614

• Short to ground in rear wiper INT switch circuit with the rear wiper switch off.

Rear wiper INT switch circuit malfunction

B1873

• Short to ground in hazard warning switch circuit with the hazard warning switch off.

Hazard warning switch circuit malfunction

B2218

• Door lock switch (driver-side) or (passenger-side) circuit voltage is less than 3.75 V with the door lock switches off.

Door lock switch (driver-side)/(passenger-side) circuit malfunction

B2574

• Short to ground in front door lock-link switch (driver-side) lock-side circuit with the front door lock-link switch (driver-side) unlocked.

Front door lock-link switch (driver-side) lock-side circuit malfunction

B257C

• Open circuit in front door lock-link switch (passenger-side), rear door lock-link switch (LH) or (RH) circuit with the door lock-link switches unlocked.

Front door lock-link switch (passenger-side)/rear door lock-link switch (LH)/(RH) circuit malfunction

B2721

• Short to ground in liftgate latch switch circuit with the liftgate closed (liftgate latch switch off).

Liftgate latch switch circuit malfunction

B2982

• Open circuit in parking brake switch circuit with the parking brake lever pulled (parking brake switch on).

Parking brake switch circuit malfunction

C1189

• Short to ground in brake fluid level sensor circuit with the brake fluid level on the upper side of the MIN.

Brake fluid level sensor circuit malfunction

C1295

• BCM detects the steering angle sensor internal abnormality (signal overflow).

Steering angle sensor internal malfunction

C1307

• BCM detects the steering angle sensor internal abnormality (signal jump).

Steering angle sensor encoder ring defective

C1441

• Open circuit in steering angle sensor A signal circuit.

Steering angle sensor A signal circuit malfunction

C1442

• Open circuit in steering angle sensor B signal circuit.

Steering angle sensor B signal circuit malfunction

C1443

• Short to ground in steering angle sensor A signal circuit.

Steering angle sensor A signal circuit malfunction

C1444

• Short to ground in steering angle sensor B signal circuit.

Steering angle sensor B signal circuit malfunction

C144A

• Short to ground in steering angle sensor C signal circuit.

Steering angle sensor C signal circuit malfunction

C144B

• Short to ground in steering angle sensor Z signal circuit.

Steering angle sensor Z signal circuit malfunction

C144C

• Open circuit in steering angle sensor C signal circuit.

Steering angle sensor C signal circuit malfunction

C144D

• Open circuit in steering angle sensor Z signal circuit.

Steering angle sensor Z signal circuit malfunction

C1937

• BCM lost the steering angle initialization position.

Steering angle sensor offset failure

U0073

• BCM detects a CAN bus communication line (HS-CAN) malfunction.

Module communication error (HS-CAN)

U0100

• BCM cannot receive the CAN signal from the PCM for 5 s or more.

Communication error with PCM

U0101

• BCM cannot receive the CAN signal from the TCM for 5 s or more.

Communication error with TCM

U0121

• BCM cannot receive the CAN signal from the DSC/RSC HU/CM for 5 s or more.

Communication error with DSC/RSC HU/CM

U0401

• BCM receives the invalid data from the PCM for 5 s or more.

Error signal from PCM

• The PID/data monitor function is used for optionally selecting input/output signal monitor items preset in the BCM and reading them out in real-time.

PID/data monitor item	Unit/Condition (Tester display)	Input/output part
BRK_FLUID	Normal/Low	• Brake fluid level above MIN: Normal • Brake fluid level below MIN: Low
CCNT_GEM	—	• DTCs detected: 1—255 • No DTCs detected: 0
CLS_LOCK	Off/Lock	• Any door open: Off • All doors closed: Lock
DRSW_D	Close/OPEN	• Front door (driver-side) closed: Close • Front door (driver-side) open: OPEN
DRSW_P	Close/OPEN	• Front door (passenger-side) closed: Close • Front door (passenger-side) open: OPEN
DRSW_REAR	Close/OPEN	• Rear door closed: Close • Rear door open: OPEN
HAZARD	Off/On	• Hazard warning switch turned off: Off • Hazard warning switch turned on: On
HOOD_SW	Close/OPEN	• Bonnet closed: Close • Bonnet open: OPEN Note • “CLOSE” is displayed on vehicles with the theft-deterrent system.
LLSW_D	Unlock/Lock	• Driver-side lock knob unlocked: Unlock • Driver-side lock knob locked: Lock
PRK_BRK	Off/On	• Parking brake not depressed (Parking brake switch in the off position): Off • Parking brake depressed (Parking brake switch in the on position): On
RWASH_SW	Off/On	• Rear washer switch in the off position: Off • Rear washer switch in the on position: On
T_GATE_SW	Close/OPEN	• Liftgate closed: Close • Liftgate open: OPEN
TURN_SW_L	Off/On	• Turn switch is in the off position: Off • Turn switch is in the LEFT position: On
TURN_SW_R	Off/On	• Turn switch is in the off position: Off • Turn switch is in the RIGHT position: On
WPINT_REAR	Off/On	• Rear wiper switch is in the OFF position: Off • Rear wiper switch is in the INT position: On