DTC B1793 Occupant Classification Sensor Power Supply Circuit Malfunction |
for Preparation Click here
DESCRIPTION
The occupant classification sensor power supply circuit consists of the occupant classification ECU and the occupant classification sensors.DTC B1793 is set when a malfunction is detected in the occupant classification sensor power supply circuit.
DTC No. | DTC Detecting Conditions | Trouble Areas |
B1793 |
|
|
- HINT:
- When DTC B1650/32 is detected as a result of troubleshooting the supplemental restraint system, perform troubleshooting for DTC B1793 of the occupant classification system.
- Use the Techstream to check for DTCs of the occupant classification ECU, otherwise the DTCs cannot be read.
WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
- If troubleshooting (wire harness inspection) is difficult to perform, remove the front RH seat assembly installation bolts to see the under surface of the seat cushion.
- In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time may cause problems, such as seat rail deformation. Hold the seat up only for as long as necessary.
1.CHECK DTC |
Turn the ignition switch to the ON position.
Clear any DTCs stored in the memory (Click here).
- HINT:
- First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
- Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
Turn the ignition switch to the LOCK position.
Turn the ignition switch to the ON position.
Using the Techstream, check for DTCs of the occupant classification ECU (Click here).
- OK:
- DTC B1793 is not output.
- HINT:
- DTCs other than B1793 may be output at this time, but they are not related to this check.
|
| ||||
NG | |
2.CHECK CONNECT CONNECTORS |
Turn the ignition switch to the LOCK position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Check that the connectors are properly connected to the occupant classification ECU and the occupant classification sensors.
- OK:
- The connectors are properly connected.
|
| ||||
OK | |
3.CHECK CONNECTORS |
Check that the connectors (on the occupant classification ECU side and the occupant classification sensors side) are not damaged (Click here).
- OK:
- The connectors are not deformed or damaged.
|
| ||||
OK | |
4.CHECK NO. 1 SEAT WIRE (TO B+) |
Disconnect the connectors from the occupant classification ECU and the 4 occupant classification sensors.
Connect the negative (-) terminal cable to the battery.
Turn the ignition switch to the ON position.
Measure the voltage.
- Standard voltage:
Tester Connection Condition Specified Condition O4-11 (SVC1) - Body ground Ignition switch ON Below 1 Ω O4-12 (SVC2) - Body ground Ignition switch ON Below 1 Ω O4-5 (SVC3) - Body ground Ignition switch ON Below 1 Ω O4-6 (SVC4) - Body ground Ignition switch ON Below 1 Ω
|
| ||||
OK | |
5.CHECK NO. 1 SEAT WIRE (TO GROUND) |
Turn the ignition switch to the LOCK position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Measure the resistance.
- Standard resistance:
Tester Connection Condition Specified Condition O4-11 (SVC1) - Body ground Always 1 MΩ or higher O4-12 (SVC2) - Body ground Always 1 MΩ or higher O4-5 (SVC3) - Body ground Always 1 MΩ or higher O4-6 (SVC4) - Body ground Always 1 MΩ or higher
|
| ||||
OK | |
6.CHECK NO. 1 SEAT WIRE (FOR OPEN) |
Measure the resistance.
- Standard resistance:
Tester Connection Condition Specified Condition O4-11 (SVC1) - O6-1 (SVC1) Always Below 1 Ω O4-12 (SVC2) - O7-1 (SVC2) Always Below 1 Ω O4-5 (SVC3) - O8-1 (SVC3) Always Below 1 Ω O4-6 (SVC4) - O9-1 (SVC4) Always Below 1 Ω
|
| ||||
OK | |
7.CHECK NO. 1 SEAT WIRE (FOR SHORT) |
Measure the resistance.
- Standard resistance:
Tester Connection Condition Specified Condition O4-5 (SVC3) - O4-6 (SVC4) Always 1 MΩ or higher O4-6 (SVC4) - O6-11 (SVC1) Always 1 MΩ or higher O4-11 (SVC1) - O4-12 (SVC2) Always 1 MΩ or higher O4-12 (SVC2) - O4-5 (SVC3) Always 1 MΩ or higher O4-12 (SVC2) - O4-6 (SVC4) Always 1 MΩ or higher O4-11 (SVC1) - O4-5 (SVC3) Always 1 MΩ or higher
|
| ||||
OK | |
8.CHECK DTC |
Connect the connectors to the occupant classification ECU and the 4 occupant classification sensors.
Connect the negative (-) terminal cable to the battery.
Turn the ignition switch to the ON position.
Clear any DTCs stored in the memory (Click here).
- HINT:
- First clear DTCs stored in the occupant classification ECU and then in the center airbag sensor assembly.
- Use the Techstream to clear the DTCs of the occupant classification ECU, otherwise the DTCs cannot be cleared.
Turn the ignition switch to the LOCK position.
Turn the ignition switch to the ON position.
Using the Techstream, check for DTCs of the occupant classification ECU (Click here).
- OK:
- DTC B1793 is not output.
- HINT:
- DTCs other than B1793 may be output at this time, but they are not related to this check.
|
| ||||
NG | |
9.REPLACE OCCUPANT CLASSIFICATION ECU |
Turn the ignition switch to the LOCK position.
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
Replace the occupant classification ECU (Click here).
- HINT:
- Perform the inspection using parts from a normal vehicle when possible.
NEXT | |
10.PERFORM ZERO POINT CALIBRATION |
Connect the negative (-) terminal cable to the battery.
Connect the Techstream to the DLC3.
Turn the ignition switch to the ON position.
Using the Techstream, perform the zero point calibration (Click here).
- OK:
- "Zero Point Calibration is complete." is displayed on the Techstream.
NEXT | |
11.PERFORM SENSITIVITY CHECK |
Using the Techstream, perform the sensitivity check (Click here).
- Standard:
- 27 to 33 kg (59.52 to 72.75 lb)
NEXT | ||
|