| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001G4RF |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 09/2022] |
| Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM (for HV Model): B1771; Passenger Side Buckle Switch Circuit Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022] | ||
|
DTC |
B1771 |
Passenger Side Buckle Switch Circuit Malfunction |
DESCRIPTION
The front passenger side buckle switch circuit consists of the occupant detection ECU and front passenger side buckle switch (front seat inner belt assembly RH).
DTC B1771 is stored when a malfunction is detected in the front passenger side buckle switch circuit.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
B1771 |
Passenger Side Buckle Switch Circuit Malfunction |
|
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
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HINT:
- When DTC B1650 is stored as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1771 is output, perform troubleshooting for this DTC first.
- If it is difficult to perform troubleshooting (wire harness inspection), remove the front passenger seat installation bolts to see under the seat cushion.
- In the above case, lift and hold the seat so that it does not fall down. Hold the seat only as necessary because holding the seat for a long period of time may cause seat rail deformation.
PROCEDURE
|
1. |
CHECK CONNECTORS |
(a) Turn the power switch off.
(b) Disconnect the cable from the negative (-) auxiliary battery terminal.
(c) Check that the connectors are properly connected to the occupant detection ECU and front seat inner belt assembly RH.
OK:
The connectors are properly connected.
HINT:
If the connectors are not properly connected, reconnect the connectors and proceed to the next inspection.
(d) Disconnect the connectors from the occupant detection ECU and front seat inner belt assembly RH.
(e) Check that the terminals of the connectors are not deformed or damaged.
OK:
The terminals are not deformed or damaged.
| NG |
|
REPLACE FRONT SEAT WIRE RH |
|
|
2. |
CHECK FRONT SEAT WIRE RH |
|
(a) Connect the cable to the negative (-) auxiliary battery terminal. |
|
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
j4-7 (BSW) - Body ground |
Power switch on (IG) |
Below 1 V |
|
j4-9 (BGND) - Body ground |
Power switch on (IG) |
Below 1 V |
(d) Turn the power switch off.
(e) Disconnect the cable from the negative (-) auxiliary battery terminal.
(f) Using a service wire, connect terminals 1 (+) and 2 (-) of connector C.
NOTICE:
Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.
(g) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
j4-7 (BSW) - j4-9 (BGND) |
Always |
Below 1 Ω |
(h) Disconnect the service wire from connector C.
(i) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
j4-7 (BSW) - j4-9 (BGND) |
Always |
1 MΩ or higher |
|
j4-7 (BSW) - Body ground |
Always |
1 MΩ or higher |
|
j4-9 (BGND) - Body ground |
Always |
1 MΩ or higher |
| NG |
|
REPLACE FRONT SEAT WIRE RH |
|
|
3. |
CHECK DTC |
(a) Connect the connectors to the occupant detection ECU and front seat inner belt assembly RH.
(b) Connect the cable to the negative (-) auxiliary battery terminal.
(c) Turn the power switch on (IG), and wait for at least 60 seconds.
(d) Clear the DTCs stored in the occupant detection ECU.
Body Electrical > Occupant Detection > Clear DTCs
(e) Clear the DTCs stored in the airbag sensor assembly.
Body Electrical > SRS Airbag > Clear DTCs
(f) Turn the power switch off.
(g) Turn the power switch on (IG), and wait for at least 10 seconds.
(h) Check for DTCs.
Body Electrical > Occupant Detection > Trouble Codes
OK:
DTC B1771 is not output.
HINT:
Codes other than DTC B1771 may be output at this time, but they are not related to this check.
(i) Turn the power switch off.
| OK |
|
|
|
4. |
CHECK FRONT SEAT INNER BELT ASSEMBLY RH |
(a) Disconnect the cable from the negative (-) auxiliary battery terminal.
(b) Replace the front seat inner belt assembly RH with a known good one.
Click here
HINT:
Perform the following inspection using known good parts from another vehicle if possible.
(c) Connect the cable to the negative (-) auxiliary battery terminal.
(d) Turn the power switch on (IG), and wait for at least 60 seconds.
(e) Clear the DTCs stored in the occupant detection ECU.
Body Electrical > Occupant Detection > Clear DTCs
(f) Clear the DTCs stored in the airbag sensor assembly.
Body Electrical > SRS Airbag > Clear DTCs
(g) Turn the power switch off.
(h) Turn the power switch on (IG), and wait for at least 10 seconds.
(i) Check for DTCs.
Body Electrical > Occupant Detection > Trouble Codes
OK:
DTC B1771 is not output.
HINT:
Codes other than DTC B1771 may be output at this time, but they are not related to this check.
(j) Turn the power switch off.
(k) Disconnect the cable from the negative (-) auxiliary battery terminal.
(l) Restore the front seat inner belt assembly RH that was installed for testing to its original location.
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| OK |
|
REPLACE FRONT SEAT INNER BELT ASSEMBLY RH
|
|
|
5. |
REPLACE OCCUPANT DETECTION ECU |
(a) Turn the power switch off.
(b) Disconnect the cable from the negative (-) auxiliary battery terminal.
(c) Replace the occupant detection ECU with a new one.
Click here
(d) Connect the cable to the negative (-) auxiliary battery terminal.
|
|
6. |
PERFORM ZERO POINT CALIBRATION |
(a) Using the Techstream, perform Zero Point Calibration.
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| NEXT |
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END |
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