ELECTRIC PARKING BRAKE SWITCH INDICATOR LIGHT IS ON OR OFF CONSTANTLY [ELECTRIC PARKING BRAKE (E)]


id040328250435

Troubleshooting item

Electric parking brake switch indicator light is on or off constantly

Description
•  Electric parking brake switch indicator light is on constantly.
•  Electric parking brake switch indicator light is off constantly.
Possible cause
•  Electric parking brake switch connector or terminal malfunction
•  Short to ground or open circuit in electric parking brake switch indicator light power supply circuit
•  Electric parking brake switch malfunction
•  DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) connector or terminal malfunction
•  Short to ground or open circuit in electric parking brake switch indicator light control circuit
•  DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) 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.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
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”.
No
Go to the next step.
3
INSPECT ELECTRIC PARKING BRAKE SWITCH CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the electric parking brake 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.
4
INSPECT ELECTRIC PARKING BRAKE SWITCH INDICATOR LIGHT POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT
•  Inspect the power supply circuit for an open circuit and short to ground.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location, and perform the repair completion verification.
5
INSPECT ELECTRIC PARKING BRAKE SWITCH
•  Inspect the electric parking brake switch.
•  Is the electric parking brake switch normal?
Yes
Go to the next step.
No
Replace the electric parking brake switch, and perform the repair completion verification.
6
INSPECT DSC HU/CM (WITHOUT Mazda M Hybrid)/ELECTRONICALLY CONTROLLED BRAKE UNIT (WITH Mazda M Hybrid) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid) 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 ELECTRIC PARKING BRAKE SWITCH INDICATOR LIGHT CONTROL CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT
•  Inspect the control circuit for an open circuit and short to ground.
•  Is the circuit normal?
Yes
Replace the DSC HU/CM (without Mazda M Hybrid)/electronically controlled brake unit (with Mazda M Hybrid), and perform the repair completion verification.
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.
If the CAN communication is normal, perform the diagnosis from Step 1.