Brake Hold Standby Indicator Light Circuit [09/2022 - ]: Procedure

1. If the brake hold standby indicator light does not illuminate even though the brake hold switch (No. 3 combination switch assembly) is pushed, check that the brake hold function operation conditions are met.
   1. The driver door is closed.
   2. The driver seat belt is fastened.
   3. The system is normal.

   HINT: 

   If a malfunction occurs in one of the following systems, the brake hold operated indicator light will blink. If this occurs, perform troubleshooting on the malfunctioning system.

   • Brake system
   • Electric parking brake system

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Enter the following menus: Chassis / Brake/EPB / Data List.

   Chassis > Brake/EPB > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Brake Hold Ready	Brake hold control permission status	Not in stand-by mode / Stand-by mode	Not in stand-by mode: Brake hold function not operating (brake hold indicator not illuminated) Stand-by mode: Brake hold function stand-by state (brake hold indicator illuminated)	-

   Chassis > Brake/EPB > Data List 

   Tester Display
   Brake Hold Ready

4. All of the following brake hold operation conditions are met:
   1. The driver door is closed.
   2. The driver seat belt is fastened.
5. Check the brake hold standby indicator light and mode condition on the Techstream changes according to brake hold switch (No. 3 combination switch assembly) operation.

   Standard

   Brake Hold Switch (No. 3 Combination Switch Assembly) Operation	Mode Condition Display	Brake Hold Standby Indicator Light
   Not pressed	Not in stand-by mode	Does not come on
   Pressing the brake hold switch (No. 3 combination switch assembly)	Stand-by mode	come on

   Result

   Result	Proceed to
   Indicator light and mode condition display do not change	A
   Mode condition display is normal, but indicator light does not change	B
   Indicator light and mode condition display are normal	C

Result: 

B 

INSPECT METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

Result: 

C 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2018 - ] 

Result: 

A 

See step  3

1. Turn the engine switch off.
2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of shift position indicator connector	*b	Front view of wire harness connector (to No. 3 Combination Switch Assembly Side Connector)
   *c	Front view of wire harness connector (to Vehicle Side Connector)	-	-

3. Disconnect the G160 and z28 shift position indicator connectors.
4. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G160-11 (+B) - z28-4 (+B)	Always	Below 1 Ω
   G160-11 (+B) or z28-4 (+B) - Body ground and other terminals	Always	10 kΩ or higher
   G160-8 (E) - z28-2 (E)	Always	Below 1 Ω
   G160-8(E) or z28-2(E) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SHIFT POSITION INDICATOR 

for UA80E: Refer to DISASSEMBLY [09/2022 - ]

for UA80F: Refer to DISASSEMBLY [09/2022 - ]

Result: 

OK 

See step  4

1. Inspect the No. 3 combination switch assembly.

   Refer to INSPECTION [06/2018 - ]

   OK

   The No. 3 combination switch assembly is normal.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE NO. 3 COMBINATION SWITCH ASSEMBLY. Refer to  REMOVAL [06/2018 - ] 

Result: 

OK 

See step  5

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

2. Disconnect the A40 skid control ECU (brake actuator assembly) connector.
3. Disconnect the G160 shift position indicator connector.
4. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A40-42 (EXI3) - G160-11 (+B)	Always	Below 1 Ω
   A40-42 (EXI3) or G160-11 (+B) - Body ground	Always	10 kΩ or higher
   G160-8 (E) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [09/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR