DTC C1A4A: Skid Control Buzzer Circuit [08/2019 - 08/2021]: 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 > DATA LIST
   
   

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   PCS Crash Alarm Buzzer	Pre-collision city buzzer status	ON or OFF	ON: Pre-collision city buzzer sounding OFF: Pre-collision city buzzer not sounding	-

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 - ] 

Result: 

B 

See step  2

1. Disconnect the A61 pre-collision city buzzer connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Pre-collision City Buzzer)

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A61-2 (IG1) - Body ground	Ignition switch ON	11 to 14 V
   	Ignition switch off	Below 1 V

3. Connect the A61 pre-collision city buzzer connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (PRE-COLLISION CITY BUZZER - BATTERY) 

Result: 

OK 

See step  3

1. Disconnect the A61 pre-collision city buzzer connector.
2. Disconnect the S12 forward recognition camera connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A61-1 (BZ) - S12-8 (BZ)	Always	Below 1 Ω
   A61-1 (BZ) or S12-8 (BZ) - Body ground	Always	10 kΩ or higher

4. Connect the S12 forward recognition camera connector.
5. Connect the A61 pre-collision city buzzer 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	Range	Normal Condition	Diagnostic Note
   PCS Crash Alarm Buzzer	Pre-collision city buzzer status	ON or OFF	ON: Pre-collision city buzzer sounding OFF: Pre-collision city buzzer not sounding	-

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 (HARNESS OR CONNECTOR (PRE-COLLISION CITY BUZZER - FORWARD RECOGNITION CAMERA) WAS DEFECTIVE) 

Result: 

B 

See step  6

1. Turn the ignition switch to ON.
2. Check if the pre-collision city buzzer is sounding.

   Result

   Result	Proceed to
   The pre-collision city buzzer does not sound when the ignition switch is ON	A
   The pre-collision city buzzer sounds continuously when the ignition switch is ON	B

Result: 

B 

See step  8

Result: 

A 

See step  7

1. Remove the pre-collision city buzzer.

   Refer to REMOVAL [08/2019 - ]

2. Inspect the pre-collision city buzzer.

   Refer to INSPECTION [08/2019 - ]

   Result

   Result	Proceed to
   Pre-collision city buzzer is abnormal	A
   Pre-collision city buzzer is normal	B

Result: 

B 

See step  9

Result: 

A 

See step  8

1. Replace the pre-collision city buzzer.

   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	Range	Normal Condition	Diagnostic Note
   PCS Crash Alarm Buzzer	Pre-collision city buzzer status	ON or OFF	ON: Pre-collision city buzzer sounding OFF: Pre-collision city buzzer not sounding	-

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  10

1. Replace the forward recognition camera.

   Refer to REMOVAL [08/2019 - ]

2. Perform forward recognition axis adjustment.

   Refer to ADJUSTMENT (SEQUENTIAL RECOGNITION) [08/2019 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  11

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	Range	Normal Condition	Diagnostic Note
   PCS Crash Alarm Buzzer	Pre-collision city buzzer status	ON or OFF	ON: Pre-collision city buzzer sounding OFF: Pre-collision city buzzer not sounding	-

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 (FORWARD RECOGNITION CAMERA WAS DEFECTIVE) 

Result: 

B 

See step  12

1. Replace the millimeter wave radar sensor assembly.

   Refer to REMOVAL [08/2019 - 08/2021]

2. Adjust the millimeter wave radar sensor assembly.

   Refer to ADJUSTMENT [08/2019 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  13

1. Clear the DTCs.

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

   Body Electrical > Pre-Collision 2 > Clear DTCs

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)