LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2016 >> 6 Touring, Standard Trans >> Repair and Diagnosis (Single Page) >> Brakes >> Parking Brake System >> On-Board Diagnostics [Electric Parking Brake] >> DTC C1128-01: Electric Parking Brake Switch Circuit Malfunction >> Diagnostic Procedure

Diagnostic Procedure

Step Inspection Action
1 INSPECT ELECTRIC PARKING BRAKE SWITCH CONNECTOR CONDITION 
  • Switch the ignition off.
  • Disconnect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)

  • 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, then go to Step 8.
2 INSPECT ELECTRIC PARKING BRAKE SWITCH 
Yes Go to the next step.
No Replace the electric parking brake switch, then go to Step 8.
(See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION .)
3 INSPECT ELECTRIC PARKING BRAKE CONTROL MODULE CONNECTOR CONDITION 
  • Disconnect the electric parking brake control module 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, then go to Step 8.
4 INSPECT ELECTRIC PARKING BRAKE SWITCH CIRCUIT FOR SHORT TO GROUND 
  • Verify that the electric parking brake switch and electric parking brake control module connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:
    • Electric parking brake switch terminal C
    • Electric parking brake switch terminal H
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Electric parking brake switch terminal C-Electric parking brake control module terminal K
  • Electric parking brake switch terminal H-Electric parking brake control module terminal M

If there is a common connector: 

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
  • Repair or replace the malfunctioning part.

If there is no common connector: 

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 8.
No Go to the next step.
5 INSPECT ELECTRIC PARKING BRAKE SWITCH CIRCUIT FOR SHORT TO POWER SUPPLY 
  • Verify that the electric parking brake switch and electric parking brake control module connectors are disconnected.
  • Connect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)

  • Switch the ignition ON (engine off or on).
  • Measure the voltage at the following terminals (wiring harness-side):
    • Electric parking brake switch terminal C
    • Electric parking brake switch terminal H
  • Is the voltage 0 V  ?
Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Electric parking brake switch terminal C-Electric parking brake control module terminal K
  • Electric parking brake switch terminal H-Electric parking brake control module terminal M

If there is a common connector: 

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
  • Repair or replace the malfunctioning part.

If there is no common connector: 

  • Repair or replace the wiring harness which has a short to power supply.

Go to Step 8.
6 INSPECT ELECTRIC PARKING BRAKE SWITCH CIRCUIT FOR OPEN CIRCUIT 
  • Switch the ignition off.
  • Disconnect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .)

  • Verify that the electric parking brake switch and electric parking brake control module connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side):
    • Electric parking brake switch terminal C-Electric parking brake control module terminal K
    • Electric parking brake switch terminal H-Electric parking brake control module terminal M
  • Is there continuity?
Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Electric parking brake switch terminal C-Electric parking brake control module terminal K
  • Electric parking brake switch terminal H-Electric parking brake control module terminal M

If there is a common connector: 

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
  • Repair or replace the malfunctioning part.

If there is no common connector: 

  • Repair or replace the wiring harness which has an open circuit.

Go to Step 8.
7 INSPECT ELECTRIC PARKING BRAKE SWITCH CIRCUITS FOR SHORT CIRCUIT 
  • Verify that the electric parking brake switch and electric parking brake control module connectors are disconnected.
  • Inspect for continuity between electric parking brake switch terminals C and H (wiring harness-side).
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Electric parking brake switch terminal C-Electric parking brake control module terminal K
  • Electric parking brake switch terminal H-Electric parking brake control module terminal M

If there is a common connector: 

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.
  • Repair or replace the malfunctioning part.

If there is no common connector: 

  • Repair or replace the wiring harness which has a short to each other.

Go to the next step.
No Go to the next step.
8 VERIFY THAT REPAIRS HAVE BEEN COMPLETED 
Yes Repeat the inspection from Step 1.

Go to the next step.
No Go to the next step.
9 VERIFY IF OTHER DTCs DISPLAYED 
  • Are any other DTCs displayed?
Yes Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [ELECTRIC PARKING BRAKE] .)
No DTC troubleshooting completed.