DTC 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-SNA0300 

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 (SRS)

1. 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.

2. Connector connection check

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

   -2. Check the following connections.

   SRS unit connector A (39P)

   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.

   NO 

   Go to step 3.

3. System check

   -1. Reset the loose 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.

   NO 

   The system is OK at this time.

4. 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 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 engine compartment wire harness): disconnected
   Test point 1	SRS unit connector A (39P) No. 31
   Test point 2	SRS unit connector A (39P) No. 32

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

   YES 

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

   NO 

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

5. 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 engine compartment wire harness): disconnected
   Test point 1	SRS unit connector A (39P) No. 31
   Test point 2	Body ground

   Test point 1	SRS unit connector A (39P) No. 32
   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.

   NO 

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

6. 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 engine compartment wire harness): disconnected
   Test point 1	SRS unit connector A (39P) No. 31
   Test point 2	Body ground

   Test point 1	SRS unit connector A (39P) No. 32
   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 engine compartment wire harness or the dashboard wire harness; replace the faulty harness, then clear the DTC.

7. 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 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 (39P): disconnected
   	Left front impact sensor 2P connector (on the engine compartment wire harness): disconnected
   	Left front impact sensor 2P connector (on the engine compartment wire harness): connected to SRS simulator lead L
   Test point 1	SRS unit connector A (39P) No. 31
   Test point 2	SRS unit connector A (39P) No. 32

   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 .

   NO 

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