DTC Troubleshooting: B280A-87

DTC B280A-87: No Signal From the Rear Safing 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 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
B280A-87 No signal from the rear safing 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
B280A-87 No signal from the rear safing sensor

Is DTC B280A-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 B (39P)

Rear safing sensor 2P connector (on the right side wire harness)

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
B280A-87 No signal from the rear safing sensor

Is DTC B280A-87 indicated?


	YES

Go to step 4.


	NO

The system is OK at this time.?

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

Shorted wire check (SSS? line to SSS? 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.

Disconnect the following connectors.

SRS unit connector B (39P)

Rear safing sensor 2P connector (on the right side wire harness)

?4.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Rear safing sensor 2P connector (on the right side wire harness): disconnected
Test point 1	SRS unit connector B (39P) No. 34
Test point 2	SRS unit connector B (39P) No. 35

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


	YES

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


	NO

Short to another wire in the right side wire harness; replace the right side wire harness, then clear the DTC.?

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

Shorted wire check (SSS?, SSS? lines)

?1.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Rear safing sensor 2P connector (on the right side wire harness): disconnected
Test point 1	SRS unit connector B (39P) No. 34
Test point 2	Body ground

Test point 1	SRS unit connector B (39P) No. 35
Test point 2	Body ground

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


	YES

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


	NO

Short to ground in the right side wire harness; replace the right side wire harness, then clear the DTC.?

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

Shorted wire check (SSS?, SSS? 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
	Rear safing sensor 2P connector (on the right side wire harness): disconnected
Test point 1	SRS unit connector B (39P) No. 34
Test point 2	Body ground

Test point 1	SRS unit connector B (39P) No. 35
Test point 2	Body ground

Is there 0.2 V or less?


	YES

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


	NO

Short to power in the right side wire harness; replace the right side wire harness, then clear the DTC.?

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

Open wire check (SSS?, SSS? lines)

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

?2.

Connect terminals A and B with a jumper wire.

Terminal A	Rear safing sensor 2P connector No. 1 (on the right side wire harness)
Terminal B	Rear safing sensor 2P connector No. 2 (on the right side wire harness)

?3.

Measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	SRS unit connector B (39P): disconnected
	Rear safing sensor 2P connector (on the right side wire harness): disconnected
	Rear safing sensor 2P connector (on the right side wire harness): connected to SRS simulator lead L
Test point 1	SRS unit connector B (39P) No. 34
Test point 2	SRS unit connector B (39P) No. 35

Is there 1.0 ? or less?


	YES

The SSS? and SSS? wires are OK. Replace the rear safing sensor, then clear the DTC, and retest. If the DTC is still present, replace the SRS unit.?


	NO

Open in the right side wire harness; replace the right side wire harness, then clear the DTC.?