| Last Modified: 04-05-2023 | 6.11:8.1.0 | Doc ID: RM1000000018YBK |
| Model Year Start: 2018 | Model: Sienna | Prod Date Range: [11/2017 - ] |
| Title: PRE-COLLISION: PRE-COLLISION SYSTEM: C1A4A; Skid Control Buzzer Circuit; 2018 - 2020 MY Sienna [11/2017 - ] | ||
|
DTC |
C1A4A |
Skid Control Buzzer Circuit |
DESCRIPTION
The driving support ECU assembly operates the pre-collision warning by sending a buzzer request signal to the skid control buzzer assembly.
If the driving support ECU assembly detects a malfunction in the skid control buzzer assembly circuit, it will store DTC C1A4A.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1A4A |
Skid Control Buzzer Circuit |
When the ignition switch is ON and the pre-collision warning is operating, either of the following conditions is met:
|
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
- When replacing the driving support ECU assembly, always replace it with a new one. If a driving support ECU assembly which was installed to another vehicle is used, the information stored in the driving support ECU assembly will not match the information from the vehicle. As a result, a DTC may be stored.
PROCEDURE
|
1. |
CHECK FOR DTCs (PRE-COLLISION SYSTEM) |
(a) Clear the DTCs.
Click here
![2018 - 2020 MY Sienna [11/2017 - ]; PRE-COLLISION: PRE-COLLISION SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)
(b) Perform the Active Test according to the display on the Techstream.
Click here
NOTICE:
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.
Pre-Collision 2
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
PCS Crash Alarm Buzzer |
Skid control buzzer assembly |
ON/OFF |
Test possible with engine switch on (IG), vehicle stopped |
(c) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
DTC C1A4A is not output |
A |
|
DTC C1A4A is output |
B |
| A |
|
|
|
2. |
CHECK TERMINAL VOLTAGE |
|
(a) Disconnect the skid control buzzer assembly connector. |
|
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A21-2 (IG1) - Body ground |
Ignition switch ON |
11 to 14 V |
|
Ignition switch off |
Below 1 V |
(c) Connect the skid control buzzer assembly connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY) |
|
|
3. |
CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY) |
(a) Disconnect the A21 skid control buzzer assembly connector.
(b) Disconnect the A80 driving support ECU assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A21-1 (BZ) - A80-3 (BZ) |
Always |
Below 1 Ω |
|
A21-1 (BZ) or A80-3 (BZ) - Body ground |
Always |
10 kΩ or higher |
(d) Connect the A80 driving support ECU assembly connector.
(e) Connect the A21 skid control buzzer assembly connector.
| OK |
|
|
|
4. |
REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY) |
(a) Repair or replace the harness or connector.
|
|
5. |
CHECK FOR DTCs (PRE-COLLISION SYSTEM) |
(a) Clear the DTCs.
Click here
Body Electrical > Pre-Collision 2 > Clear DTCs
(b) Perform the Active Test according to the display on the Techstream.
Click here
NOTICE:
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.
Pre-Collision 2
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
PCS Crash Alarm Buzzer |
Skid control buzzer assembly |
ON/OFF |
Test possible with engine switch on (IG), vehicle stopped |
(c) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
DTC C1A4A is not output |
A |
|
DTC C1A4A is output |
B |
| A |
|
END |
|
|
6. |
INSPECT SKID CONTROL BUZZER ASSEMBLY (CONFIRM BUZZER OPERATION) |
(a) Turn the ignition switch to ON.
(b) Check if the skid control buzzer assembly is sounding.
|
Result |
Proceed to |
|---|---|
|
The skid control buzzer assembly does not sound when the ignition switch is ON |
A |
|
The skid control buzzer assembly sounds continuously when the ignition switch is ON |
B |
| B |
|
|
|
7. |
INSPECT SKID CONTROL BUZZER ASSEMBLY (UNIT INSPECTION) |
(a) Remove the skid control buzzer assembly.
Click here
(b) Inspect the skid control buzzer assembly.
Click here
|
Result |
Proceed to |
|---|---|
|
Skid control buzzer assembly is abnormal |
A |
|
Skid control buzzer assembly is normal |
B |
| B |
|
|
|
8. |
REPLACE SKID CONTROL BUZZER ASSEMBLY |
(a) Replace the skid control buzzer assembly.
Click here
|
|
9. |
CHECK FOR DTCs (PRE-COLLISION SYSTEM) |
(a) Clear the DTCs.
Click here
Body Electrical > Pre-Collision 2 > Clear DTCs
(b) Perform the Active Test according to the display on the Techstream.
Click here
NOTICE:
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.
Pre-Collision 2
|
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
PCS Crash Alarm Buzzer |
Skid control buzzer assembly |
ON/OFF |
Test possible with engine switch on (IG), vehicle stopped |
(c) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
DTC C1A4A is not output |
A |
|
DTC C1A4A is output |
B |
| A |
|
END |
| B |
|
|
|