DTC Troubleshooting: B0091-87, B0092-87 - Honda Civic FC/FK 2016-2021

1.

DTC check:

DTC check

?1.	Clear the DTCs with the HDS.

?2.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?3.

Check for DTCs with the HDS.

DTC Description	DTC
B0091-4A Internal failure of the left side impact sensor (first)
B0091-87 No signal from the left side impact sensor (first)
B0091-92 Internal failure of the left side impact sensor (first)
B0092-4A Internal failure of the left side impact sensor (second)
B0092-87 No signal from the left side impact sensor (second)
B0092-92 Internal failure of the left side impact sensor (second)

Are DTCs indicated?


	DTC B0091-87

Go to step 2.


	DTC B0092-87

Go to step 10.


	DTC B0091-4A or B0091-92

Replace the left side impact sensor (first), then clear the DTC.?


	DTC B0092-4A or B0092-92

Replace the left side impact sensor (second), then clear the DTC.?


	NO DTC

Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.?

2.

Harness visual check:

Harness visual check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Check the damage on the floor wire harness that side impact sensor is connected to.

Is the floor wire harness OK?


	YES

Go to step 3.


	NO

Replace the floor wire harness, then clear the DTC, and retest.

3.

Connector connection check:

Connector connection check

?1.

Check the following connections.

SRS unit connector B (39P)

Left side impact sensor (first) 4P connector (on the floor wire harness)

Left side impact sensor (second) 2P connector (on the floor wire harness)

Are the connectors OK?


	YES

Go to step 5.


	NO

Go to step 4.

4.

System check:

System check

?1.	Reset the loose connections that caused the problem in step 3.

?2.	Clear the DTCs with the HDS.

?3.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?4.

Check for DTCs with the HDS.

DTC Description	DTC
B0091-87 No signal from the left side impact sensor (first)

Is DTC B0091-87 indicated?


	YES

Turn the vehicle to the OFF (LOCK) mode, then go to step 5.


	NO

The system is OK at this time.?

5.

Left side impact sensor (first) substituting:

Left side impact sensor (first) substituting

?1.	Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

?2.	Substitute a known-good left side impact sensor (first).

?3.	Reconnect the negative cable to the 12 volt battery.

?4.	Clear the DTCs with the HDS.

?5.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?6.

Check for DTCs with the HDS.

DTC Description	DTC
B0091-87 No signal from the left side impact sensor (first)

Is DTC B0091-87 indicated?


	YES

Go to step 6.


	NO

Replace the left side impact sensor (first), then clear the DTC.?

6.

Shorted wire check (LS1? line to LS1? line):

Shorted wire check (LS1? line to LS1? line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

?3.	Return the left side impact sensor (first) which was replaced.

?4.

Disconnect the following connectors.

SRS unit connector B (39P)

Left side impact sensor (first) 4P connector (on the floor wire harness)

Left side impact sensor (second) 2P connector (on the floor wire harness)

?5.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
Test point 2	Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)

Is there an open circuit, or at least 1 M??


	YES

The LS1? and LS1? wires are not shorted. Go to step 7.


	NO

Short to another wire in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.?

7.

Shorted wire check (LS1?, LS1? lines):

Shorted wire check (LS1?, LS1? lines)

?1.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
Test point 2	Body ground

Test point 1	Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
Test point 2	Body ground

Is there an open circuit, or at least 1 M??


	YES

The LS1? and LS1? wires are not shorted. Go to step 8.


	NO

Short to ground in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.?

8.

Shorted wire check (LS1?, LS1? lines to power):

Shorted wire check (LS1?, LS1? lines to power)

?1.	Reconnect the negative cable to the 12 volt battery.

?2.	Turn the vehicle to the ON mode.

?3.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)
Test point 2	Body ground

Test point 1	Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)
Test point 2	Body ground

Is there 0.2 V or less?


	YES

The LS1? and LS1? wires are not shorted to power. Go to step 9.


	NO

Short to power in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.?

9.

Open wire check (LS1?, LS1? lines):

Open wire check (LS1?, LS1? lines)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	SRS unit connector B (39P) No. 38
Test point 2	Left side impact sensor (first) 4P connector No. 3 (on the floor wire harness)

Test point 1	SRS unit connector B (39P) No. 39
Test point 2	Left side impact sensor (first) 4P connector No. 2 (on the floor wire harness)

Is there 1.0 ? or less?


	YES

The LS1? and LS1? wires are OK. Disconnect and reconnect the connector, and then check the DTC again. If the DTC is still present, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit.?


	NO

Open in the floor wire harness between the SRS unit and the left side impact sensor (first); replace the floor wire harness, then clear the DTC.?

10.

Harness visual check:

Harness visual check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Check the damage on the floor wire harness that side impact sensor is connected to.

Is the floor wire harness OK?


	YES

Go to step 11.


	NO

Replace the floor wire harness, then clear the DTC, and retest.

11.

Connector connection check:

Connector connection check

?1.

Check the following connections.

SRS unit connector B (39P)

Left side impact sensor (first) 4P connector (on the floor wire harness)

Left side impact sensor (second) 2P connector (on the floor wire harness)

Are the connectors OK?


	YES

Go to step 13.


	NO

Go to step 12.

12.

System check:

System check

?1.	Reset the loose connections that caused the problem in step 11.

?2.	Clear the DTCs with the HDS.

?3.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?4.

Check for DTCs with the HDS.

DTC Description	DTC
B0092-87 No signal from the left side impact sensor (second)

Is DTC B0092-87 indicated?


	YES

Turn the vehicle to the OFF (LOCK) mode, then go to step 13.


	NO

The system is OK at this time.?

13.

Left side impact sensor (second) substituting:

Left side impact sensor (second) substituting

?1.	Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

?2.	Substitute a known-good left side impact sensor (second).

?3.	Reconnect the negative cable to the 12 volt battery.

?4.	Clear the DTCs with the HDS.

?5.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?6.

Check for DTCs with the HDS.

DTC Description	DTC
B0092-87 No signal from the left side impact sensor (second)

Is DTC B0092-87 indicated?


	YES

Go to step 14.


	NO

Replace the left side impact sensor (second), then clear the DTC.?

14.

Left side impact sensor (first) substituting:

Left side impact sensor (first) substituting

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

?3.	Return the left side impact sensor (second) which was replaced.

?4.	Substitute a known-good left side impact sensor (first).

?5.	Reconnect the negative cable to the 12 volt battery.

?6.	Clear the DTCs with the HDS.

?7.	Turn the vehicle to the ON mode, then wait for 10 seconds.

?8.

Check for DTCs with the HDS.

DTC Description	DTC
B0092-87 No signal from the left side impact sensor (second)

Is DTC B0092-87 indicated?


	YES

Go to step 15.


	NO

Replace the left side impact sensor (first), then clear the DTC.?

15.

Shorted wire check (LS2? line to LS2? line):

Shorted wire check (LS2? line to LS2? line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

?3.	Return the left side impact sensor (first) which was replaced.

?4.

Disconnect the following connectors.

SRS unit connector B (39P)

Left side impact sensor (first) 4P connector (on the floor wire harness)

Left side impact sensor (second) 2P connector (on the floor wire harness)

?5.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (second) 2P connector No. 1 (on the floor wire harness)
Test point 2	Left side impact sensor (second) 2P connector No. 2 (on the floor wire harness)

Is there an open circuit, or at least 1 M??


	YES

The LS2? and LS2? wires are not shorted. Go to step 16.


	NO

Short to another wire in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.?

16.

Shorted wire check (LS2?, LS2? lines):

Shorted wire check (LS2?, LS2? lines)

?1.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (second) 2P connector No. 1 (on the floor wire harness)
Test point 2	Body ground

Test point 1	Left side impact sensor (second) 2P connector No. 2 (on the floor wire harness)
Test point 2	Body ground

Is there an open circuit, or at least 1 M??


	YES

The LS2? and LS2? wires are not shorted. Go to step 17.


	NO

Short to ground in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.?

17.

Shorted wire check (LS2?, LS2? lines to power):

Shorted wire check (LS2?, LS2? lines to power)

?1.	Reconnect the negative cable to the 12 volt battery.

?2.	Turn the vehicle to the ON mode.

?3.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (second) 2P connector No. 1 (on the floor wire harness)
Test point 2	Body ground

Test point 1	Left side impact sensor (second) 2P connector No. 2 (on the floor wire harness)
Test point 2	Body ground

Is there 0.2 V or less?


	YES

The LS2? and LS2? wires are not shorted to power. Go to step 18.


	NO

Short to power in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.?

18.

Open wire check (LS2?, LS2? lines):

Open wire check (LS2?, LS2? lines)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Left side impact sensor (first) 4P connector (on the floor wire harness): disconnected
	Left side impact sensor (second) 2P connector (on the floor wire harness): disconnected
Test point 1	Left side impact sensor (first) 4P connector No. 1 (on the floor wire harness)
Test point 2	Left side impact sensor (second) 2P connector No. 2 (on the floor wire harness)

Test point 1	Left side impact sensor (first) 4P connector No. 4 (on the floor wire harness)
Test point 2	Left side impact sensor (second) 2P connector No. 1 (on the floor wire harness)

Is there 1.0 ? or less?


	YES

The LS2? and LS2? wires are OK. Disconnect and reconnect the connector, and then check the DTC again. If the DTC is still present, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit.?


	NO

Open in the floor wire harness between the left side impact sensor (first) and the left side impact sensor (second); replace the floor wire harness, then clear the DTC.?