No.9 BRIGHTNESS LEVEL OF RVM WARNING INDICATOR LIGHTS IS TOO HIGH OR LOW [REAR VEHICLE MONITORING SYSTEM]

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9	Brightness level of RVM warning indicator lights is too high or low
DESCRIPTION	•  RVM warning indicator lights brightness level is low in the daytime (headlights off) (correct level is retained at night) •  RVM warning indicator lights brightness level is high at night (headlights on) (correct level is retained in the daytime) •  RVM warning indicator lights brightness level is low during dimmer cancel function operation (correct level is retained while dimmer cancel function is not operating) •  RVM warning indicator lights brightness level is high while dimmer cancel function is not operating (correct level is retained during dimmer cancel function operation)
POSSIBLE CAUSES	•  Rear vehicle monitoring control module (RH) does not receive correct TNS switch signal from BCM ―  Open circuit in wiring harness between TNS switch (light switch) terminal A (L.H.D.)/K (R.H.D.) and BCM terminal 2V ―  Open circuit in wiring harness between TNS switch (light switch) terminal E (L.H.D.)/G (R.H.D.) and ground ―  Short circuit to ground in wiring harness between TNS switch (light switch) terminal A (L.H.D.)/K (R.H.D.) and BCM termin al 2V ―  TNS switch (light switch) malfunction (stuck) ―  BCM malfunction ―  Communication error between BCM and rear vehicle monitoring control module (RH) •  Rear vehicle monitoring control module (RH) does not receive dimmer cancel signal correctly from instrument cluster ―  Communication error between instrument cluster and rear vehicle monitoring control module (RH) ―  Rear vehicle monitoring control module (RH) malfunction (Dimmer cancel signal is not received) ―  Instrument cluster malfunction (Dimmer cancel signal is not output) •  Rear vehicle monitoring control module (LH) does not receive TNS switch signal and dimmer cancel signal from rear vehicle monitoring control module (RH). ―  Communication error between rear vehicle monitoring control modules (RH and LH)

Diagnostic Procedure

Warning

•  When performing a road test, always verify the safety of the surrounding area before performing the test.

•  To assure safety, perform a road test using two people when the vehicle is being driven. (One drives the vehicle and the other operates the M-MDS.)

•  Do not perform a road test at a speed which exceeds the legal speed limit.

Step	Inspection		Action
1	VERIFY DTCs •  Retrieve DTCs from rear vehicle monitoring system and BCM using the M-MDS. (See DTC INSPECTION [REAR VEHICLE MONITORING SYSTEM].) (See DTC INSPECTION [BCM].) •  Are any DTCs displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [REAR VEHICLE MONITORING SYSTEM].) (See DTC TABLE [BCM].)
		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS INPUT SIGNAL OR RVM WARNING INDICATOR LIGHTS ILLUMINATION CIRCUIT RELATED •  Monitor the following rear vehicle monitoring system PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION [REAR VEHICLE MONITORING SYSTEM].) ―  OP_BRT_R ―  OP_BRT_L •  Perform the ON/OFF operation of the headlight switch (TNS switch) and the instrument cluster dimmer cancel function. Note •  While the dimmer function is canceled, the PID monitoring value increases (brighter) with the headlights on. •  Does the monitoring value change according to headlight switch and dimmer cancel operation?	Yes	Replace the rear vehicle monitoring control module (LH). (See REAR VEHICLE MONITORING CONTROL MODULE REMOVAL/INSTALLATION.)
		No	Go to the next step.
3	VERIFY INSTRUMENT CLUSTER DIMMER CANCEL FUNCTION OPERATION •  Verify that the dimmer cancel function of the instrument cluster is operating correctly. •  Is the dimmer release function operating correctly?	Yes	Go to the next step.
		No	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
4	VERIFY TNS SIGNAL •  Turn on the light switch. •  Measure the terminal voltage at BCM terminal 2V. (See BODY CONTROL MODULE (BCM) INSPECTION.) •  Is the voltage normal?	Yes	Replace the rear vehicle monitoring control module (RH). (See REAR VEHICLE MONITORING CONTROL MODULE REMOVAL/INSTALLATION.)
		No	Go to the next step.
5	INSPECT TNS SIGNAL WIRING HARNESS •  Switch the ignition to off (LOCK). •  Inspect the wiring harness between the following terminals for an open or short circuit. ―  Between light switch terminal A (L.H.D.)/K (R.H.D.) and BCM terminal 2V ―  Light switch terminal B and ground •  Is the wiring harness normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning part.
6	INSPECT LIGHT SWITCH •  Inspect the light switch. (See LIGHT SWITCH INSPECTION.) •  Is the light switch normal?	Yes	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [L.H.D.].) (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [R.H.D.].)
		No	Replace the light switch. (See LIGHT SWITCH REMOVAL/INSTALLATION.)