DTC Troubleshooting: B0090-87

DTC B0090-87: No Signal From the Left Front Impact Sensor

Special Tools Required

?SRS Inflator Simulator 07SAZ-TB4011A

?SRS Simulator Lead L 070AZ-SNAA300

NOTE:

	Before doing this troubleshooting procedure, find out if the vehicle was in a collision. If so, verify that all the required components were replaced with new components of the correct part number, and that they were properly installed.
	Before doing this troubleshooting procedure, review SRS Precautions and Procedures, General Troubleshooting Information, and 12 Volt Battery Terminal Disconnection and Reconnection.
	Before replacing the SRS unit, check the SRS unit software version with the HDS. If the software version is not the latest, update the SRS unit software, and retest.

DTC Description	DTC
B0090-87 No signal from the left front impact sensor

Problem verification:

Problem verification

?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
B0090-87 No signal from the left front impact sensor

Is DTC B0090-87 indicated?


	YES

The failure is duplicated. Go to step 2.


	NO

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

Connector connection check:

Connector connection check

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

?2.

Check the following connector connections.

SRS unit connector A (39P)

Left front impact sensor 2P connector (on the left engine compartment wire harness)

Connector between the SRS unit and the left front impact sensor

Are the connectors OK?


	YES

Go to step 4.


	NO

Go to step 3.

System check:

System check

?1.	Repair the poor connector connections whichever was the cause of the problem in step 2.

?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
B0090-87 No signal from the left front impact sensor

Is DTC B0090-87 indicated?


	YES

Turn the vehicle to the OFF (LOCK) mode, then go to step 4.


	NO

The system is OK at this time.?

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

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

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

?2.

Disconnect the following connectors.

SRS unit connector A (39P)

Left front impact sensor 2P connector (on the left engine compartment wire harness)

?3.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector A (39P): disconnected
	Left front impact sensor 2P connector (on the left engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (39P) No. 28
Test point 2	SRS unit connector A (39P) No. 29

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


	YES

The LFS? and LFS? wires are not shorted. Go to step 5.


	NO

Short to another wire in the left engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.?

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

Shorted wire check (LFS?, LFS? lines)

?1.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector A (39P): disconnected
	Left front impact sensor 2P connector (on the left engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (39P) No. 28
Test point 2	Body ground

Test point 1	SRS unit connector A (39P) No. 29
Test point 2	Body ground

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


	YES

The LFS? and LFS? wires are not shorted. Go to step 6.


	NO

Short to ground in the left engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.?

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

Shorted wire check (LFS?, LFS? 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 A (39P): disconnected
	Left front impact sensor 2P connector (on the left engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (39P) No. 28
Test point 2	Body ground

Test point 1	SRS unit connector A (39P) No. 29
Test point 2	Body ground

Is there 0.2 V or less?


	YES

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


	NO

Short to power in the left engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.?

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

Open wire check (LFS?, LFS? lines)

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

?2.	Connect the black terminal (A) of SRS simulator lead L to the SRS inflator simulator (jumper connector), then connect SRS simulator lead L to the left front impact sensor 2P connector (B) on the left engine compartment wire harness.

?3.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector A (39P): disconnected
	Left front impact sensor 2P connector (on the left engine compartment wire harness): disconnected
	Left front impact sensor 2P connector (on the left engine compartment wire harness): connected to SRS simulator lead L
Test point 1	SRS unit connector A (39P) No. 28
Test point 2	SRS unit connector A (39P) No. 29

Is there 1.0 ? or less?


	YES

The LFS? and LFS? wires are OK. Replace the left front impact sensor, then clear the DTC, and retest. If the DTC is still present, replace the SRS unit.?


	NO

Open in the left engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.?