"CHK" message(s) are displayed on the SIGNAL CHECK screen. [02/2019 - 12/2021]: Procedure

1. Check which items display on the signal check screen.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *A	w/ Retract Mirror
   *a	Example

   Result

   Result	Proceed to
   "CAMERA SW" displays "CHK" (red)	A
   "CAN" displays "CHK" (red)	B
   "SHIFT" displays "CHK" (red)	C
   "MIRROR SW" displays "CHK" (red) (w/ Retract Mirror)	D

Result: 

B 

GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [02/2019 - ] 

Result: 

C 

See step  4

Result: 

D 

See step  6

Result: 

A 

See step  2

1. Disconnect the G37 panoramic view monitor switch connector.
2. Disconnect the N25 parking assist ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G37-5 (D) - N25-15 (BLSW)	Always	Below 1 Ω
   G37-2 (E) - Body ground	Always	Below 1 Ω
   G37-5 (D) or N25-15 (BLSW) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Remove the panoramic view monitor switch.

   Refer to REMOVAL [11/2018 - ]

2. Inspect the panoramic view monitor switch.

   Refer to INSPECTION [11/2018 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE PARKING ASSIST ECU. Refer to  REMOVAL [11/2018 - 10/2022] 

Result: 

NG 

REPLACE PANORAMIC VIEW MONITOR SWITCH. Refer to  REMOVAL [11/2018 - ] 

1. Check that the back-up light comes on.

   OK

   The back-up light comes on.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO LIGHTING SYSTEM (EXT) 

w/ Headlight ECU without AFS: Refer to PROBLEM SYMPTOMS TABLE [11/2018 - 08/2020] , or refer to PROBLEM SYMPTOMS TABLE [08/2020 - 12/2021]

w/o Headlight ECU: Refer to PROBLEM SYMPTOMS TABLE [02/2019 - 08/2020] , or refer to PROBLEM SYMPTOMS TABLE [08/2020 - 12/2021]

w/ AFS: Refer to PROBLEM SYMPTOMS TABLE [02/2019 - 08/2020] , or refer to PROBLEM SYMPTOMS TABLE [08/2020 - 12/2021]

Result: 

OK 

See step  5

1. Disconnect the parking assist ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Parking Assist ECU)

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   N25-14 (REV) - Body ground	Power switch on (IG), shift lever in R	11 to 14 V
   N25-14 (REV) - Body ground	Power switch on (IG), shift lever not in R	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE PARKING ASSIST ECU. Refer to  REMOVAL [11/2018 - 10/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the J13 outer rear view mirror assembly LH connector.
2. Disconnect the N25 parking assist ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   J13-5 (MF) - N25-16 (MPOS)	Always	Below 1 Ω
   J13-5 (MF) or N25-16 (MPOS) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

GO TO POWER MIRROR CONTROL SYSTEM. Refer to  PROBLEM SYMPTOMS TABLE [11/2018 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR