DTC B0090-87

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

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 were properly installed .
Before doing this troubleshooting procedure, review SRS Precautions and Procedures , General Troubleshooting Information , and 12 Volt Battery Terminal Disconnection and Reconnection. .

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

DTC (SRS)

Problem verification

-1. Apply the parking brake.

-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

The failure is duplicated. Go to step 2.

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

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

-2. Check the following connections.

SRS unit connector A (43P)

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

Connector between the SRS unit and the left front impact sensor

Are the connectors OK?

YES

Go to step 4.

Go to step 3.

System check

-1. Reset the loose connector connections that caused 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.

The system is OK at this time.

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 (43P)

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

-3. Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector A (43P): disconnected
	Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (43P) No. 32
Test point 2	SRS unit connector A (43P) No. 33

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

YES

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

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

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 (43P): disconnected
	Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (43P) No. 32
Test point 2	Body ground

Test point 1	SRS unit connector A (43P) No. 33
Test point 2	Body ground

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

YES

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

Short to ground in the 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)

-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 (43P): disconnected
	Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
Test point 1	SRS unit connector A (43P) No. 32
Test point 2	Body ground

Test point 1	SRS unit connector A (43P) No. 33
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.

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

Open wire check (LFS+, LFS- lines)

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

-2. Connect terminals A and B with a jumper wire.

Terminal A	Left front impact sensor 2P connector (female terminals) No. 1 (on the engine compartment wire harness):
Terminal B	Left front impact sensor 2P connector (female terminals) No. 2 (on the engine compartment wire harness):

Courtesy of HONDA, U.S.A., INC.

-3. Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector A (43P): disconnected
	Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
	Left front impact sensor 2P connector terminals No. 1 and No. 2(on the engine compartment wire harness): jumped
Test point 1	SRS unit connector A (43P) No. 32
Test point 2	SRS unit connector A (43P) No. 33

Is there 1.0 Ω 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, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit .

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