AIRBAG SYSTEM (DIAGNOSTICS) > Diagnostic Chart with Trouble Code
DTC B1820 SHORT IN SIDE AIRBAG RH
Diagnosis start condition:
Ignition voltage is 10 V to 16 V.
DTC detecting condition:
• Side airbag harness (RH) circuit is shorted.
• Side airbag module (RH) is faulty.
• Airbag control module is faulty.
CAUTION:
Before performing diagnosis, refer to “CAUTION” in “General Description”. General Description > CAUTION">
Wiring diagram:
Airbag system Airbag System > WIRING DIAGRAM">

| STEP | CHECK | YES | NO |
1.CHECK POOR CONTACT OF CONNECTORS.
Check for poor contact of the connectors between the airbag control module, side airbag module RH and the side airbag sensor RH.
Is there poor contact?
Replace the airbag rear harness along with body harness.
Diagnostic Chart with Trouble Code > DTC B1820 SHORT IN SIDE AIRBAG RH">Go to Step 2.
2.CHECK SIDE AIRBAG MODULE.
1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
2) Disconnect the connector (AB24) from the side airbag module (RH), and connect the connector (1AJ) in the test harness AJ to connector (AB24).
3) Connect the airbag resistor to the test harness AJ connector (3AJ).
4) Connect the battery ground terminal and turn the ignition switch to ON.
Does the airbag warning light illuminate for 6 seconds and go off?
Replace the side airbag module (RH). Side Airbag Module > REMOVAL">
Diagnostic Chart with Trouble Code > DTC B1820 SHORT IN SIDE AIRBAG RH">Go to Step 3.
3.CHECK AIRBAG REAR HARNESS (SIDE AIRBAG MODULE HARNESS RH).
1) Turn the ignition switch to OFF, disconnect the battery ground cable, and wait for 60 seconds or more.
2) Disconnect the connector (AB26) from seat belt pretensioner (RH).
3) Disconnect the connector (AB33) from curtain airbag module (RH).
4) Disconnect the airbag resistor from test harness AJ.
5) Disconnect the connectors (AB6, AB17, AB18) from airbag control module.
6) Connect the connector (1AG) in the test harness AG to the connectors (AB6, AB17, AB18).
7) Measure the resistance between connector (5AG) in the test harness AG and chassis ground.
Connector & terminal
(5AG) No. 5 — (5AG) No. 7:
Is the resistance 1 M? or more?
Diagnostic Chart with Trouble Code > DTC B1820 SHORT IN SIDE AIRBAG RH">Go to Step 4.
Replace the airbag rear harness along with body harness.
4.CHECK AIRBAG CONTROL MODULE.
1) Connect all connectors.
2) Clear the memory. Clear Memory Mode">
3) Perform the Inspection Mode. Inspection Mode">
4) Read the DTC. (Current malfunction) Read Diagnostic Trouble Code (DTC)">
Is DTC B1820 displayed?
Replace the airbag control module. Airbag Control Module">
Diagnostic Chart with Trouble Code > DTC B1820 SHORT IN SIDE AIRBAG RH">Go to Step 5.
5.CHECK FOR ANY OTHER DTC ON DISPLAY.
Is any other DTC displayed?
Check DTC using “List of Diagnostic Trouble Code (DTC)”. List of Diagnostic Trouble Code (DTC)">
Finish the diagnosis.
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NOTE
This section applies specifically to the following Subaru Ascent component.
second-row (window-side) seatbelt
In the Subaru Ascent, the second-row window-side seatbelts are equipped with
advanced shoulder belt pretensioners that automatically activate during significant
frontal, ...
Note
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Ignition switch light (if equipped)
For easy access to the ignition switch in
the dark, the ignition switch light illuminates
when the driver's door is opened or
when the driver's door is unlocked using
the remote keyless entry transmitter.
The light remains illuminated for several
tens of seconds and then gradually turns
off ...