DTC C1128:29 [ELECTRIC PARKING BRAKE]

id040257250800

Description	Electric parking brake switch circuit malfunction
Detection condition	• Electric parking brake control module detects an electric parking brake switch circuit malfunction.
Fail-safe	• The electric parking brake control module operates the electric parking brake under any of the following conditions while the vehicle is stopped. ? Ignition is switched ON (engine off or on) and selector lever is in P or N position ? Ignition is switched ON (engine off or on) and driver's door is open from closed condition ? Ignition is switched off and brake pedal is depressed ? Ignition is switched off and driver's door is open
Possible cause	• Electric parking brake switch connector or terminal malfunction • Electric parking brake switch malfunction • Electric parking brake control module connector or terminal malfunction • Short to power supply in wiring harness between the following terminals: ? Electric parking brake switch terminal C—Electric parking brake control module terminal 2K ? Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q ? Electric parking brake switch terminal G—Electric parking brake control module terminal 2L ? Electric parking brake switch terminal H—Electric parking brake control module terminal1W • Open circuit in wiring harness between the following terminals: ? Electric parking brake switch terminal C—Electric parking brake control module terminal 2K ? Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q ? Electric parking brake switch terminal G—Electric parking brake control module terminal 2L ? Electric parking brake switch terminal H—Electric parking brake control module terminal 1W • Short circuit between electric parking brake switch circuits • Electric parking brake control module malfunction

Diagnostic Procedure

Step	Inspection		Action
1	INSPECT ELECTRIC PARKING BRAKE SWITCH CONNECTOR CONDITION • Switch the ignition OFF. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the electric parking brake switch connector. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.) • 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.
1		No	Repair or replace the connector, then go to Step 7.
2	INSPECT ELECTRIC PARKING BRAKE SWITCH • Inspect the electric parking brake switch. (See ELECTRIC PARKING BRAKE SWITCH INSPECTION.) • Is the electric parking brake switch normal?	Yes	Go to the next step.
2		No	Replace the electric parking brake switch, then go to Step 7. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.)
3	INSPECT ELECTRIC PARKING BRAKE CONTROL MODULE CONNECTOR CONDITION • Disconnect the electric parking brake switch connector. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.) • 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.
3		No	Repair or replace the connector, then go to Step 7.
4	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 terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • 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 E ? Electric parking brake switch terminal G ? Electric parking brake switch terminal H • Is the voltage 0 V?	Yes	Go to the next step.
4		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 2K • Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q • Electric parking brake switch terminal G—Electric parking brake control module terminal 2L • Electric parking brake switch terminal H—Electric parking brake control module terminal 1W 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 7.
5	INSPECT ELECTRIC PARKING BRAKE SWITCH CIRCUIT FOR OPEN CIRCUIT • Switch the ignition OFF. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • 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 2K ? Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q ? Electric parking brake switch terminal G—Electric parking brake control module terminal 2L ? Electric parking brake switch terminal H—Electric parking brake control module terminal 1W • Is there continuity?	Yes	Go to the next step.
5		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 2K • Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q • Electric parking brake switch terminal G—Electric parking brake control module terminal 2L • Electric parking brake switch terminal H—Electric parking brake control module terminal 1W 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 7.
6	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, E, G, 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 2K • Electric parking brake switch terminal E—Electric parking brake control module terminal 2Q • Electric parking brake switch terminal G—Electric parking brake control module terminal 2L • Electric parking brake switch terminal H—Electric parking brake control module terminal 1W 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.
6		No	Go to the next step.
7	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Always reconnect all disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC for the electric parking brake control module using the M-MDS. (See CLEARING DTC [ELECTRIC PARKING BRAKE].) • Perform the following procedure 3 times or more. ? Pull up the electric parking brake switch to operate the electric parking brake. ? Press down the electric parking brake switch to release the electric parking brake. • Retrieve the electric parking brake control module DTCs using the M-MDS. (See DTC INSPECTION [ELECTRIC PARKING BRAKE].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the electric parking brake control module. (See ELECTRIC PARKING BRAKE CONTROL MODULE REMOVAL/INSTALLATION.) Go to the next step.
7		No	Go to the next step.
8	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].)
8		No	DTC troubleshooting completed.