Parking Brake Switch Circuit [06/2017 - ]: Procedure

1. Choose the model to be inspected.

   Result

   Result	Proceed to
   w/o Electric Parking Brake System	A
   w/ Electric Parking Brake System	B

Result: 

B 

See step  4

Result: 

A 

See step  2

1. Check that the brake warning light comes on when the parking brake is applied and goes off when it is released.

   OK

   The brake warning light operates as specified above.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2017 - 10/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - ] 

Result: 

OK 

See step  3

1. Disconnect the K2 radio and display receiver assembly connector.
2. Disconnect the A4 parking brake switch assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   K2-20 (PKB) - A4-1	Always	Below 1 Ω
   K2-20 (PKB) or A4-1 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [06/2017 - 08/2018]  , or refer to  PROBLEM SYMPTOMS TABLE [08/2018 - 09/2019]  , or refer to  PROBLEM SYMPTOMS TABLE [09/2019 - 10/2020]  , or refer to  PROBLEM SYMPTOMS TABLE [10/2020 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Check that the brake warning light comes on when the parking brake is applied and goes off when it is released.

   OK

   The brake warning light operates as specified above.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2017 - 10/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2020 - ] 

Result: 

OK 

See step  5

1. Disconnect the K2 radio and display receiver assembly connector.
2. Disconnect the A34 skid control ECU (brake actuator assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   K2-20 (PKB) - A34-33 (PKB)	Always	Below 1 Ω
   K2-20 (PKB) or A34-33 (PKB) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [06/2017 - 08/2018]  , or refer to  PROBLEM SYMPTOMS TABLE [08/2018 - 09/2019]  , or refer to  PROBLEM SYMPTOMS TABLE [09/2019 - 10/2020]  , or refer to  PROBLEM SYMPTOMS TABLE [10/2020 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR