DTC C0023:14 [REAR BODY CONTROL MODULE (RBCM)]

id0902p4015100

Description

Brake light circuit malfunction

Detection condition

•  Rear body control module (RBCM) detects any of the following conditions:

―  Brake lights/high-mount brake light illuminated even though driver or system does not illuminate brake lights/high-mount brake light.

―  Brake lights/high-mount brake light not illuminated even though driver depresses brake pedal.

―  Brake lights/high-mount brake light not illuminated even though system illuminates brake lights/high-mount brake light.

Fail-safe

•  Not applicable

Possible cause

•  Rear combination light (LH) connector or terminal malfunction

•  Open circuit in wiring harness between the following:

―  Rear combination light (LH) terminal E—Body ground (4SD)

―  Rear combination light (LH) terminal A—Body ground (WGN)

•  Rear combination light (RH) connector or terminal malfunction

•  Open circuit in wiring harness between the following:

―  Rear combination light (RH) terminal E—Body ground (4SD)

―  Rear combination light (RH) terminal A—Body ground (WGN)

•  High-mount brake light connector or terminal malfunction

•  Open circuit in wiring harness between high-mount brake light terminal A and body ground

•  Brake light unit connector or terminal malfunction

•  Rear body control module (RBCM) connector or terminal malfunction

•  Short to ground in wiring harness between the following terminals:

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Brake light unit terminal J

―  High-mount brake light terminal B—Brake light unit terminal G

•  Short to power supply in wiring harness between the following terminals:

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Brake light unit terminal J

―  High-mount brake light terminal B—Brake light unit terminal G

•  Open circuit in wiring harness between the following terminals:

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN)

―  Rear body control module (RBCM) terminal 4D—Brake light unit terminal J

―  Rear body control module (RBCM) terminal 2H—Brake light unit terminal D

―  High-mount brake light terminal B—Brake light unit terminal G

•  Rear combination light (LH) malfunction

•  Rear combination light (RH) malfunction

•  High-mount brake light malfunction

•  Brake light unit malfunction

•  Rear body control module (RBCM) malfunction

Description	Brake light circuit malfunction
Detection condition	• Rear body control module (RBCM) detects any of the following conditions: ― Brake lights/high-mount brake light illuminated even though driver or system does not illuminate brake lights/high-mount brake light. ― Brake lights/high-mount brake light not illuminated even though driver depresses brake pedal. ― Brake lights/high-mount brake light not illuminated even though system illuminates brake lights/high-mount brake light.
Fail-safe	• Not applicable
Possible cause	• Rear combination light (LH) connector or terminal malfunction • Open circuit in wiring harness between the following: ― Rear combination light (LH) terminal E—Body ground (4SD) ― Rear combination light (LH) terminal A—Body ground (WGN) • Rear combination light (RH) connector or terminal malfunction • Open circuit in wiring harness between the following: ― Rear combination light (RH) terminal E—Body ground (4SD) ― Rear combination light (RH) terminal A—Body ground (WGN) • High-mount brake light connector or terminal malfunction • Open circuit in wiring harness between high-mount brake light terminal A and body ground • Brake light unit connector or terminal malfunction • Rear body control module (RBCM) connector or terminal malfunction • Short to ground in wiring harness between the following terminals: ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Brake light unit terminal J ― High-mount brake light terminal B—Brake light unit terminal G • Short to power supply in wiring harness between the following terminals: ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Brake light unit terminal J ― High-mount brake light terminal B—Brake light unit terminal G • Open circuit in wiring harness between the following terminals: ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Brake light unit terminal J ― Rear body control module (RBCM) terminal 2H—Brake light unit terminal D ― High-mount brake light terminal B—Brake light unit terminal G • Rear combination light (LH) malfunction • Rear combination light (RH) malfunction • High-mount brake light malfunction • Brake light unit malfunction • Rear body control module (RBCM) malfunction

Diagnostic Procedure

Step	Inspection		Action
1	VERIFY REAR BODY CONTROL MODULE (RBCM) DTCs AGAIN • Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC [REAR BODY CONTROL MODULE (RBCM)].) • Depress the brake pedal. • Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION [REAR BODY CONTROL MODULE (RBCM)].) • Is the same Pending DTC present?	Yes	Go to the next step.
1		No	Go to Step 17.
2	INSPECT REAR COMBINATION LIGHT (LH) CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the rear combination light (LH) 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.
2		No	Repair or replace the connector, then go to Step 16.
3	INSPECT FOR OPEN CIRCUIT IN BRAKE LIGHT (LH) (COMBINATION LIGHT (LH)) GROUND CIRCUIT • Verify that the rear combination light (LH) connector is disconnected. • Inspect for continuity between the following harnesses: ― Rear combination light (LH) terminal E—Body ground (4SD) ― Rear combination light (LH) terminal A—Body ground (WGN) • Is there continuity?	Yes	Go to the next step.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Rear combination light (LH) terminal E—Body ground (4SD) • Rear combination light (LH) terminal A—Body ground (WGN) 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 16.
4	INSPECT REAR COMBINATION LIGHT (RH) CONNECTOR CONDITION • Disconnect the rear combination light (RH) 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, then go to Step 16.
5	INSPECT FOR OPEN CIRCUIT IN BRAKE LIGHT (RH) (COMBINATION LIGHT (RH)) GROUND CIRCUIT • Verify that the rear combination light (RH) connector is disconnected. • Inspect for continuity between the following harnesses: ― Rear combination light (RH) terminal E—Body ground (4SD) ― Rear combination light (RH) terminal A—Body ground (WGN) • 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: • Rear combination light (RH) terminal E—Body ground (4SD) • Rear combination light (RH) terminal A—Body ground (WGN) 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 16.
6	INSPECT HIGH-MOUNT BRAKE LIGHT CONNECTOR CONDITION • Disconnect the high-mount brake light 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.
6		No	Repair or replace the connector, then go to Step 16.
7	INSPECT FOR OPEN CIRCUIT IN HIGH-MOUNT BRAKE LIGHT GROUND CIRCUIT • Verify that the high-mount brake light connector is disconnected. • Inspect for continuity between high-mount brake light terminal A (wiring harness-side) and body ground. • Is there continuity?	Yes	Go to the next step.
7		No	Refer to the wiring diagram and verify whether or not there is a common connector between high-mount brake light terminal A 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. Go to Step 16.
8	INSPECT BRAKE LIGHT UNIT CONNECTOR CONDITION • Disconnect the brake light unit 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.
8		No	Repair or replace the connector, then go to Step 16.
9	INSPECT REAR BODY CONTROL MODULE (RBCM) CONNECTOR CONDITION • Disconnect the rear body control module (RBCM) 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.
9		No	Repair or replace the connector, then go to Step 16.
10	INSPECT BRAKE LIGHT CIRCUIT FOR SHORT TO GROUND • Verify that the rear combination light (LH), rear combination light (RH), high-mount brake light, brake light unit and rear body control module (RBCM) connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side) and body ground: ― Rear body control module (RBCM) terminal 4D ― High-mount brake light terminal B • Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Brake light unit terminal J • High-mount brake light terminal B—Brake light unit terminal G 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 16.
10		No	Go to the next step.
11	INSPECT FOR SHORT TO POWER SUPPLY IN BRAKE LIGHT CIRCUIT • Verify that the rear combination light (LH), rear combination light (RH), high-mount brake light, brake light unit and rear body control module (RBCM) connectors are disconnected. • Reconnect 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): ― Rear body control module (RBCM) terminal 4D ― High-mount brake light terminal B • Is the voltage 0 V?	Yes	Go to the next step.
11		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Brake light unit terminal J • High-mount brake light terminal B—Brake light unit terminal G 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 16.
12	INSPECT FOR OPEN CIRCUIT BRAKE LIGHT CIRCUIT • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Verify that the rear combination light (LH), rear combination light (RH), high-mount brake light, brake light unit and rear body control module (RBCM) connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) ― Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) ― Rear body control module (RBCM) terminal 4D—Brake light unit terminal J ― Rear body control module (RBCM) terminal 2H—Brake light unit terminal D ― High-mount brake light terminal B—Brake light unit terminal G • Is there continuity?	Yes	Go to the next step.
12		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal B (4SD) • Rear body control module (RBCM) terminal 4D—Rear combination light (LH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Rear combination light (RH) terminal C (WGN) • Rear body control module (RBCM) terminal 4D—Brake light unit terminal J • Rear body control module (RBCM) terminal 2H—Brake light unit terminal D • High-mount brake light terminal B—Brake light unit terminal G 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 16.
13	INSPECT BRAKE LIGHT • Reconnect the rear combination light (LH), rear combination light (RH), and rear body control module (RBCM) connectors. • Verify that the brake light unit connector is disconnected. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Turn on/off the brake light using simulation item STOP_LMP_CS. (See ACTIVE COMMAND MODES INSPECTION [REAR BODY CONTROL MODULE (RBCM)].) • Are there any lights among the following which are not turned on/off according to the simulation operation? ― Brake light (LH) (rear combination light (LH)) ― Brake light (RH) (rear combination light (RH))	Yes	If the brake light (LH) (rear combination light (LH)) does not turn on/off: • Replace the rear combination light (LH). (See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.) If the brake light (RH) (rear combination light (RH)) does not turn on/off: • Replace the rear combination light (RH). (See REAR COMBINATION LIGHT REMOVAL/INSTALLATION.) Go to Step 16.
13		No	Go to the next step.
14	PERFORM DTC INSPECTION AND VERIFY HIGH-MOUNT BRAKE LIGHT MALFUNCTION • Always reconnect all disconnected connectors. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC [REAR BODY CONTROL MODULE (RBCM)].) • Depress the brake pedal. • Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION [REAR BODY CONTROL MODULE (RBCM)].) • Is the same Pending DTC present?	Yes	Replace the high-mount brake light, then go to the next step. (See HIGH-MOUNT BRAKE LIGHT REMOVAL/INSTALLATION.)
14		No	Go to Step 17.
15	INSPECT BRAKE LIGHT UNIT • Inspect the brake light unit. (See BRAKE LIGHT UNIT INSPECTION.) • Is the brake light unit normal?	Yes	Go to the next step.
15		No	Replace the brake light unit, then go to the next step. (See BRAKE LIGHT UNIT REMOVAL/INSTALLATION.)
16	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Always reconnect all disconnected connectors. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC [REAR BODY CONTROL MODULE (RBCM)].) • Depress the brake pedal. • Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION [REAR BODY CONTROL MODULE (RBCM)].) • Is the same Pending DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the rear body control module (RBCM). (See REAR BODY CONTROL MODULE (RBCM) REMOVAL/INSTALLATION.) Go to the next step.
16		No	Go to the next step.
17	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 [REAR BODY CONTROL MODULE (RBCM)].)
17		No	DTC troubleshooting completed.