Diagnostic Procedure

Step	Inspection		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 CMDTC self-test using the M-MDS. (See DTC INSPECTION [ELECTRIC PARKING BRAKE] .) Are any DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [ELECTRIC PARKING BRAKE] .)
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] .)
2		No	ATX: Replace the electric parking brake control module. (See ELECTRIC PARKING BRAKE CONTROL MODULE REMOVAL .) (See ELECTRIC PARKING BRAKE CONTROL MODULE INSTALLATION .) MTX: Go to the next step.
3	VERIFY IF BACK-UP LIGHTS ARE ILLUMINATED Shift the shift lever to the reverse position. Are the back-up lights illuminated?	Yes	Replace the electric parking brake control module. (See ELECTRIC PARKING BRAKE CONTROL MODULE REMOVAL .) (See ELECTRIC PARKING BRAKE CONTROL MODULE INSTALLATION .)
3		No	Go to the next step.
4	INSPECT BACK-UP LIGHT SWITCH CONNECTOR CONDITION Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5] .) Disconnect the back-up light 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.
4		No	Repair or replace the connector.
5	INSPECT BACK-UP LIGHT SWITCH Inspect the back-up light switch. (See BACK-UP LIGHT SWITCH INSPECTION .) Is the back-up light switch normal?	Yes	Go to the next step.
5		No	Replace the back-up light switch. (See BACK-UP LIGHT SWITCH REMOVAL/INSTALLATION [C66M-R] .)
6	INSPECT BACK-UP LIGHT SWITCH GROUND CIRCUIT FOR OPEN CIRCUIT Verify that the back-up light switch connector is disconnected. Inspect the wiring harness for continuity between back-up light switch terminal D (wiring harness-side) and body ground. Is there continuity?	Yes	Go to the next step.
6		No	Refer to the wiring diagram and verify whether or not there is a common connector between back-up light switch terminal D and body ground. 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.
7	INSPECT PCM CONNECTOR CONDITION Disconnect the PCM 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.
7		No	Repair or replace the connector.
8	INSPECT BACK-UP LIGHT SWITCH CIRCUIT FOR SHORT TO GROUND Verify that the back-up light switch and PCM connectors are disconnected. Inspect for continuity between back-up light switch terminal A (wiring harness-side) and body ground. Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between back-up light switch terminal A and PCM terminal 1L. 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.
8		No	Go to the next step.
9	INSPECT BACK-UP LIGHT SWITCH CIRCUIT FOR SHORT TO POWER SUPPLY Verify that the back-up light switch and PCM 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 back-up light switch terminal A (wiring harness-side). Is the voltage 0 V ?	Yes	Go to the next step.
9		No	Refer to the wiring diagram and verify whether or not there is a common connector between back-up light switch terminal A and PCM terminal 1L. 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.
10	INSPECT BACK-UP LIGHT 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 back-up light switch and PCM connectors are disconnected. Inspect the wiring harness for continuity between back-up light switch terminal A (wiring harness-side) and PCM terminal 1L (wiring harness-side). Is there continuity?	Yes	Replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5] .)
10		No	Refer to the wiring diagram and verify whether or not there is a common connector between back-up light switch terminal A and PCM terminal 1L. 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.