B1478

B1478

Component Location:

General Description
Curtain Airbag (hereinafter referred to CAB) is located at driver and passenger side of headliner. It protects passenger's head and shoulder from fragments of glass or something sharpen caused by overturn. CAB is consist of air bag and inflator. Air bag reduces impact of collision by filled up gas. Inflator keeps gas and uses it to deploy air bag on collision.

CAUTION: Never measure resistance of CAB directly, Current of measuring device may cause unexpected air bag deploy.

DTC Description
The SRSCM sets DTC B1478 if the measured resistance value of PCAB circuit is less than the threshold value.
*In this case, SRSCM checks if there's any fault in circuit by sending current for a while.

DTC Detecting Condition:

Specification:

Schematic Diagram:

Monitor Scantool Data
1. Ignition "OFF", connect scantool.
2. Ignition "ON"& Engine "OFF", select "Diagnostic Trouble Codes (DTC)" mode.
3. Monitor diagnostic trouble code and present of trouble code.
4. Using a scan tool, clear the DTC.






5. Is DTC present problem?

YES
a. Go to "W/Harness Inspection" procedure.

NO
a. Displaying nothing (no DTC) or DTC with label "H" (historical) shows that Fault is intermittent caused by poor contact in the part's and/or SRSCM connector or was repaired and SRSCM memory was not cleared. Thoroughly check shorting bar/shorting bar release pin and connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
b. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check shorting bar/shorting bar release pin and connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?

YES
a. Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

NO
a. Go to " Squib Circuit Inspection" procedure.

Squib Circuit Inspection
4. Ignition "OFF".
5. Disconnect (-) terminal cable from battery and wait for 1 minute or more.
6. Disconnect PCAB module and connect the dummy (0957A-38200) and dummy adapter (0957A-1C000) to main harness connector.

CAUTION: If dummy and dummy adaptor are not able to be prepared, use a known-good PCAB or 2 ohms resistor.

7. Connect (-) terminal cable to battery and Ignition "ON" & Engine "OFF" and wait for 30 seconds or more.
8. Connect scantool to Data Link Connector (DLC) and clear DTC with scantool and diagnose again.






9. Is DTC present problem?

YES
a. Go to "Main harness circuit inspection" procedure.

NO
a. Substitute a known-good PCAB assembly, and check for proper operation. If the problem is corrected, replace PCAB and then go to "Verification of Vehicle Repair" procedure.

Main harness Circuit Inspection
10. Ignition "OFF"
11. Disconnect the battery (-) terminal cable from the battery and wait at least one minute.
12. Disconnect PCAB connector and SRSCM main harness connector.
13. Measure resistance between terminal "2" and "1" of the PCAB harness connector.

a. Specification : approx. 1 ohm below






14. Is the measured resistance within specifications?

YES
a. Substitute a known-good SRSCM, and check for proper operation. If the problem is corrected, replace SRSCM and then go to "Verification of Vehicle Repair" procedure.

NO
a. Substitute the SRS main harness and check for proper operation. If the problem is corrected, replace SRS main harness and then go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTC)" mode
2. Using a scan tool, clear the DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTC present?

YES
a. Go to the applicable troubleshooting procedure.

NO
a. System is performing to specification at this time.