ELECTRIC PARKING BRAKE CANNOT BE RELEASED [ELECTRIC PARKING BRAKE (E)]

id040328250835

Note

• If it is necessary to move the vehicle as in an emergency, perform the electric parking brake forced release. (See ELECTRIC PARKING BRAKE FORCED RELEASE PROCEDURE.)

Troubleshooting item

Electric parking brake cannot be released

Description

•  The electric parking brake cannot be released even though the electric parking brake release operation has been performed.

Possible cause

•  Electric parking brake operation malfunction (if there is a malfunction in electric parking brake, DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) detects DTC)

•  Rear brake sticking (rear disc plate is retained even though electric parking brake motor gear unit operates release)

System Wiring Diagram

•  Not applicable

Troubleshooting item	Electric parking brake cannot be released
Description	• The electric parking brake cannot be released even though the electric parking brake release operation has been performed.
Possible cause	• Electric parking brake operation malfunction (if there is a malfunction in electric parking brake, DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) detects DTC) • Rear brake sticking (rear disc plate is retained even though electric parking brake motor gear unit operates release)
System Wiring Diagram	• Not applicable

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

Inspect the rear braking for sticking and repair or replace the malfunctioning location.

(See REAR BRAKE DISC REMOVAL/INSTALLATION.)

(See REAR BRAKE CALIPER DISASSEMBLY/ASSEMBLY [(E)].)

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.

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	Inspect the rear braking for sticking and repair or replace the malfunctioning location. (See REAR BRAKE DISC REMOVAL/INSTALLATION.) (See REAR BRAKE CALIPER DISASSEMBLY/ASSEMBLY [(E)].) 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.