DTC C1A4A: Skid Control Buzzer Circuit [08/2019 - ]: Procedure

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

2. Perform the Active Test according to the display on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [08/2019 - ]

   NOTE:

   Perform the Active Test for 1 second or more.

   HINT: 

   Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

   BODY ELECTRICAL > PRE-COLLISION 2 > ACTIVE TEST
   
   

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   PCS Collision Alarm Buzzer	Skid control buzzer assembly	ON / OFF	Test possible with engine switch on (IG), vehicle stopped

3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

   Result

   Result	Proceed to
   DTC C1A4A is not output	A
   DTC C1A4A is output	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - 08/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2020 - 08/2021]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2021 - 08/2022]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2022 - ] 

Result: 

B 

See step  2

1. Disconnect the A9 skid control buzzer assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A9-2 (IG1) - Body ground	Engine switch on (IG)	11 to 14 V
   	Engine switch off	Below 1 V

3. Connect the A9 skid control buzzer assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY) 

Result: 

OK 

See step  3

1. Disconnect the A9 skid control buzzer assembly connector.
2. Disconnect the G114 driving support ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A9-1 (BZ) - G114-3 (BZ)	Always	Below 1 Ω
   A9-1 (BZ) or G114-3 (BZ) - Body ground	Always	10 kΩ or higher

4. Connect the G114 driving support ECU assembly connector.
5. Connect the A9 skid control buzzer assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  6

Result: 

NG 

See step  4

1. Repair or replace the harness or connector.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

2. Perform the Active Test according to the display on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [08/2019 - ]

   NOTE:

   Perform the Active Test for 1 second or more.

   HINT: 

   Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

   BODY ELECTRICAL > PRE-COLLISION 2 > ACTIVE TEST
   
   

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   PCS Collision Alarm Buzzer	Skid control buzzer assembly	ON / OFF	Test possible with engine switch on (IG), vehicle stopped

3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

   Result

   Result	Proceed to
   DTC C1A4A is not output	A
   DTC C1A4A is output	B

Result: 

A 

END 

Result: 

B 

See step  6

1. Turn the engine switch on (IG).
2. Check if the skid control buzzer is sounding.

   Result

   Result	Proceed to
   The skid control buzzer assembly does not sound when the engine switch is on (IG)	A
   The skid control buzzer assembly sounds continuously when the engine switch is on (IG)	B

Result: 

B 

See step  8

Result: 

A 

See step  7

1. Remove the skid control buzzer assembly.

   Refer to REMOVAL [08/2019 - ]

2. Inspect the skid control buzzer assembly.

   Refer to INSPECTION [08/2019 - ]

   Result

   Result	Proceed to
   Skid control buzzer assembly is abnormal	A
   Skid control buzzer assembly is normal	B

Result: 

B 

See step  9

Result: 

A 

See step  8

1. Replace the skid control buzzer assembly.

   Refer to REMOVAL [08/2019 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  9

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

2. Perform the Active Test according to the display on the Techstream.

   Refer to DATA LIST / ACTIVE TEST [08/2019 - ]

   NOTE:

   Perform the Active Test for 1 second or more.

   HINT: 

   Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.

   BODY ELECTRICAL > PRE-COLLISION 2 > ACTIVE TEST
   
   

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   PCS Collision Alarm Buzzer	Skid control buzzer assembly	ON / OFF	Test possible with engine switch on (IG), vehicle stopped

3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [08/2019 - ]

   Result

   Result	Proceed to
   DTC C1A4A is not output	A
   DTC C1A4A is output	B

Result: 

A 

END 

Result: 

B 

REPLACE DRIVING SUPPORT ECU ASSEMBLY. Refer to  REMOVAL [08/2019 - ]