Brake Warning Light Remains ON [11/2016 - ]: Procedure

1. Check if ABS, VSC and/or electronically controlled brake system DTCs are output.

   Refer to DTC CHECK / CLEAR [02/2014 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output.	A
   DTCs are output.	B

Result:  2

B 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2016 - ] 

Result:  1

A 

See step  2

1. Check if CAN communication system DTCs are output.

   Refer to DIAGNOSIS SYSTEM [11/2016 - ]

   Result

   Result	Proceed to
   DTCs are not output.	A
   DTCs are output.	B

Result:  2

B 

INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2016 - ] 

Result:  1

A 

See step  3

1. Check if the skid control ECU assembly connector is securely connected.

   OK

   The connector is securely connected.

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

CONNECT CONNECTOR TO SKID CONTROL ECU ASSEMBLY CORRECTLY 

Result:  1

OK 

See step  4

1. Check the auxiliary battery voltage.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Auxiliary battery	Power switch on (IG)	11 to 14 V
   Auxiliary battery	Power switch on (READY)	11 to 15.5 V

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

CHARGE OR REPLACE AUXILIARY BATTERY 

Result:  1

OK 

See step  5

1. Disconnect the A63 skid control ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU Assembly)

2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A63-2 (IG1) - Body ground	Power switch on (IG)	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT) 

Result:  1

OK 

See step  6

1. Turn the power switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Front view of wire harness connector (to Skid Control ECU Assembly)

   -

   -

2. Disconnect the A65, A62 and A64 skid control ECU assembly connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A62-1 (GND) - Body ground	Always	Below 1 Ω
   A63-3 (GND2) - Body ground	Always	Below 1 Ω
   A63-1 (GND3) - Body ground	Always	Below 1 Ω
   A64-3 (GND4) - Body ground	Always	Below 1 Ω
   A64-1 (GND5) - Body ground	Always	Below 1 Ω
   A65-3 (GND6) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

Result:  1

OK 

See step  7

1. Select the Data List on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Brake Warning Light	Brake warning light / red (malfunction)	ON or OFF	ON: Warning light on OFF: Warning light off	-

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display
   Brake Warning Light

2. Check the Techstream display condition of the brake warning light / red (malfunction).

   Result

   Result	Proceed to
   Display of the Data List remains OFF.	A
   Display of the Data List remains ON.	B

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the parts.

   Refer to PROBLEM SYMPTOMS TABLE [02/2014 - ]

Result:  1

A 

INSPECT METER / GAUGE SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [02/2014 - ] 

Result:  2

B 

REPLACE SKID CONTROL ECU ASSEMBLY. Refer to  REMOVAL [02/2014 - ]