ELECTRIC PARKING BRAKE AUTOMATIC RELEASE FUNCTION DURING ACCELERATION DOES NOT OPERATE [ELECTRIC PARKING BRAKE (E)]

id040328250535

Troubleshooting item

Electric parking brake automatic release function during acceleration does not operate

Description

•  Electric parking brake automatic release function during acceleration does not operate.

Possible cause

•  DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) malfunction

•  Front door latch and lock actuator (driver’s side) connector or terminal malfunction

•  Front door latch switch (driver’s side) malfunction

•  Door-electrical supply unit, driver connector or terminal malfunction

•  Short to ground in front door latch switch (driver’s side) signal circuit

•  Door-electrical supply unit, driver malfunction

•  Driver-side buckle switch connector or terminal malfunction

•  Driver-side buckle switch malfunction

•  Dash-electrical supply unit connector or terminal malfunction

•  Short to ground in driver-side buckle switch signal circuit

•  Dash-electrical supply unit malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

VERIFY ALL SYSTEM DTCs

•  Switch the ignition off.

•  Switch the ignition ON (engine off or on) and wait for 10 s or more.

•  Perform a DTC inspection using the M-MDS.
(See DTC INSPECTION.)

•  Are any DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [DSC HU/CM (E)].)

(See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)

No

Go to the next step.

2

VERIFY IF THE ELECTRIC PARKING BRAKE WARNING LIGHT IS TURNED ON

•  Verify if the electric parking brake warning light is turned on.

•  Is the electric parking brake warning light turned on?

Yes

Perform an inspection referring to “ELECTRIC PARKING BRAKE WARNING LIGHT TURNS ON”.

(See ELECTRIC PARKING BRAKE WARNING LIGHT TURNS ON [ELECTRIC PARKING BRAKE (E)].)

No

Go to the next step.

3

DETERMINE MALFUNCTIONING LOCATION BY PERFORMING PID/DATA MONITOR INSPECTION

•  Using the M-MDS, display the following PIDs for the door-electrical supply unit, driver.
(See PID/DATA MONITOR INSPECTION.)

―  DOOR_SW_D (Front door (driver’s side) open/closed condition)

•  Using the M-MDS, display the following PIDs for the dash-electrical supply unit.
(See PID/DATA MONITOR INSPECTION.)

―  SEAT_B_STAT (Driver's seat belt fastened)

•  Does the PID monitoring value switch correctly in conjunction with the opening/closing of the front door (driver’s side) or with the driver's seat belt fastened?

Yes

Replace the DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid), and perform the repair completion verification.

(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (E)].)

(See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].)

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].)

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)

No

Not in conjunction with front door (driver’s side) open/close

•  Go to the next step.

Not in conjunction with driver's seat belt fastened

•  Go to Step 8.

4

INSPECT FRONT DOOR LATCH AND LOCK ACTUATOR (DRIVER’S SIDE) CONNECTOR CONDITION

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION [(E)].)

•  Disconnect the front door latch and lock actuator (driver’s side) connector.

•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

•  Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, and perform the repair completion verification.

5

INSPECT FRONT DOOR LATCH SWITCH (DRIVER’S SIDE)

•  Inspect the front door latch switch (driver’s side).
(See FRONT DOOR LATCH AND LOCK ACTUATOR INSPECTION [(E)].)

•  Is the front door latch switch (driver’s side) normal?

Yes

Go to the next step.

No

Replace the front door latch and lock actuator (driver’s side), and perform the repair completion verification.

(See FRONT DOOR LATCH AND LOCK ACTUATOR REMOVAL/INSTALLATION.)

6

INSPECT DOOR-ELECTRICAL SUPPLY UNIT,DRIVER CONNECTOR CONDITION

•  Disconnect the door-electrical supply unit, driver connector.

•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

•  Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, and perform the repair completion verification.

7

INSPECT FRONT DOOR LATCH SWITCH (DRIVER’S SIDE) SIGNAL CIRCUIT FOR SHORT TO GROUND

•  Inspect the signal circuit for a short to ground.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Replace the door-electrical supply unit, and perform the repair completion verification.

(See DOOR-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION.)

No

Repair or replace the malfunctioning location, and perform the repair completion verification.

8

INSPECT DRIVER-SIDE BUCKLE SWITCH CONNECTOR CONDITION

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION [(E)].)

•  Disconnect the driver-side buckle switch connector.

•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

•  Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, and perform the repair completion verification.

9

INSPECT DRIVER-SIDE BUCKLE SWITCH

•  Inspect the driver-side buckle switch.
(See BUCKLE SWITCH INSPECTION [(E)].)

•  Is the driver-side buckle switch normal?

Yes

Go to the next step.

No

Replace the driver-side front buckle, and perform the repair completion verification.

(See FRONT BUCKLE REMOVAL/INSTALLATION [(E)].)

10

INSPECT DASH-ELECTRICAL SUPPLY UNIT CONNECTOR CONDITION

•  Disconnect the dash-electrical supply unit connector.

•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

•  Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, and perform the repair completion verification.

11

INSPECT DRIVER-SIDE BUCKLE SWITCH SIGNAL CIRCUIT FOR SHORT TO GROUND

•  Inspect the signal circuit for a short to ground.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Replace the dash-electrical supply unit, and perform the repair completion verification.

(See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].)

(See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].)

No

Repair or replace the malfunctioning location, and perform the repair completion verification.

Repair completion verification

VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Has the malfunction symptom been eliminated?

Yes

Complete the symptom troubleshooting.

Explain to the customer what has been repaired.

No

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

Troubleshooting item	Electric parking brake automatic release function during acceleration does not operate
Description	• Electric parking brake automatic release function during acceleration does not operate.
Possible cause	• DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) malfunction • Front door latch and lock actuator (driver’s side) connector or terminal malfunction • Front door latch switch (driver’s side) malfunction • Door-electrical supply unit, driver connector or terminal malfunction • Short to ground in front door latch switch (driver’s side) signal circuit • Door-electrical supply unit, driver malfunction • Driver-side buckle switch connector or terminal malfunction • Driver-side buckle switch malfunction • Dash-electrical supply unit connector or terminal malfunction • Short to ground in driver-side buckle switch signal circuit • Dash-electrical supply unit malfunction

Step	Inspection	Results	Action
1	VERIFY ALL SYSTEM DTCs • Switch the ignition off. • Switch the ignition ON (engine off or on) and wait for 10 s or more. • Perform a DTC inspection using the M-MDS. (See DTC INSPECTION.) • Are any DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [DSC HU/CM (E)].) (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
1		No	Go to the next step.
2	VERIFY IF THE ELECTRIC PARKING BRAKE WARNING LIGHT IS TURNED ON • Verify if the electric parking brake warning light is turned on. • Is the electric parking brake warning light turned on?	Yes	Perform an inspection referring to “ELECTRIC PARKING BRAKE WARNING LIGHT TURNS ON”. (See ELECTRIC PARKING BRAKE WARNING LIGHT TURNS ON [ELECTRIC PARKING BRAKE (E)].)
2		No	Go to the next step.
3	DETERMINE MALFUNCTIONING LOCATION BY PERFORMING PID/DATA MONITOR INSPECTION • Using the M-MDS, display the following PIDs for the door-electrical supply unit, driver. (See PID/DATA MONITOR INSPECTION.) ― DOOR_SW_D (Front door (driver’s side) open/closed condition) • Using the M-MDS, display the following PIDs for the dash-electrical supply unit. (See PID/DATA MONITOR INSPECTION.) ― SEAT_B_STAT (Driver's seat belt fastened) • Does the PID monitoring value switch correctly in conjunction with the opening/closing of the front door (driver’s side) or with the driver's seat belt fastened?	Yes	Replace the DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid), and perform the repair completion verification. (See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (E)].) (See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)
3		No	Not in conjunction with front door (driver’s side) open/close • Go to the next step. Not in conjunction with driver's seat belt fastened • Go to Step 8.
4	INSPECT FRONT DOOR LATCH AND LOCK ACTUATOR (DRIVER’S SIDE) CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION [(E)].) • Disconnect the front door latch and lock actuator (driver’s side) connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is the connector normal?	Yes	Go to the next step.
4		No	Repair or replace the connector, and perform the repair completion verification.
5	INSPECT FRONT DOOR LATCH SWITCH (DRIVER’S SIDE) • Inspect the front door latch switch (driver’s side). (See FRONT DOOR LATCH AND LOCK ACTUATOR INSPECTION [(E)].) • Is the front door latch switch (driver’s side) normal?	Yes	Go to the next step.
5		No	Replace the front door latch and lock actuator (driver’s side), and perform the repair completion verification. (See FRONT DOOR LATCH AND LOCK ACTUATOR REMOVAL/INSTALLATION.)
6	INSPECT DOOR-ELECTRICAL SUPPLY UNIT,DRIVER CONNECTOR CONDITION • Disconnect the door-electrical supply unit, driver connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is the connector normal?	Yes	Go to the next step.
6		No	Repair or replace the connector, and perform the repair completion verification.
7	INSPECT FRONT DOOR LATCH SWITCH (DRIVER’S SIDE) SIGNAL CIRCUIT FOR SHORT TO GROUND • Inspect the signal circuit for a short to ground. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Replace the door-electrical supply unit, and perform the repair completion verification. (See DOOR-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION.)
7		No	Repair or replace the malfunctioning location, and perform the repair completion verification.
8	INSPECT DRIVER-SIDE BUCKLE SWITCH CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION [(E)].) • Disconnect the driver-side buckle switch connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is the connector normal?	Yes	Go to the next step.
8		No	Repair or replace the connector, and perform the repair completion verification.
9	INSPECT DRIVER-SIDE BUCKLE SWITCH • Inspect the driver-side buckle switch. (See BUCKLE SWITCH INSPECTION [(E)].) • Is the driver-side buckle switch normal?	Yes	Go to the next step.
9		No	Replace the driver-side front buckle, and perform the repair completion verification. (See FRONT BUCKLE REMOVAL/INSTALLATION [(E)].)
10	INSPECT DASH-ELECTRICAL SUPPLY UNIT CONNECTOR CONDITION • Disconnect the dash-electrical supply unit connector. • Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. • Is the connector normal?	Yes	Go to the next step.
10		No	Repair or replace the connector, and perform the repair completion verification.
11	INSPECT DRIVER-SIDE BUCKLE SWITCH SIGNAL CIRCUIT FOR SHORT TO GROUND • Inspect the signal circuit for a short to ground. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Replace the dash-electrical supply unit, and perform the repair completion verification. (See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (E)].) (See DASH-ELECTRICAL SUPPLY UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (E)].)
11		No	Repair or replace the malfunctioning location, and perform the repair completion verification.
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR • Install/connect the part removed/disconnected during the troubleshooting procedure. • Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. Explain to the customer what has been repaired.
Repair completion verification		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1.