Restraint > SRSCM > Troubleshooting > B1371 STPS(Seat Track Position Sensor)-Driver instability

General Description

STPS located underneath driver seat detects horizental position of driver seat and delivers it to SRSCM. Signal of STPS is the one of major parameters that determine the way dual output type airbag deploys.

DTC Description

The SRSCM sets DTC B1371 if the value of driver side STPS changes frequently.

DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

•	Check current(PWM type)

•	Poor connection of connected part.

•	Faulty STPS.

•	Faulty SRSCM.

Enable Conditions

•	Ignition "ON"

Diagnostic
Time

Qualification

•

2 sec

De-Qualification

•

N/A

Schematic Diagram

Monitor Scantool Data

1.	Ignition "OFF", connect scantool.

2.	Ignition "ON" & Engine "OFF", select "Diagnostic Trouble Codes(DTC)" mode.

3.	Monitor diagnostic trouble code and present of trouble code.

4.	Using a scan tool, clear the DTC.

Is DTC present problem ?

▶ Go to "W/Harness Inspection" procedure.

▶ Displaying nothing(no DTC) or DTC with label "H"(historical) shows that Fault is intermittent caused by poor contact in the part's and/or SRSCM connector or was repaired and SRSCM memory was not cleared.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
▶ Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

Terminal and Connector Inspection

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Component Inspection" procedure.

Component Inspection

1.	Ignition "ON" & Engine "OFF" and Using a scan tool, clear the DTC.

2.	Ignition "OFF".

3.	Disconnect the battery (-) terminal cable from the battery, and wait at least one minutes.

4.	Disconnect STPS connector .

5.	Substitute the STPS and check for proper operation

Is DTC present problem ?

	▶ Substitute a known-good SRSCM, and check for proper operation. If the problem is corrected, replace SRSCM and then go to "Verification of Vehicle Repair" procedure. ▶ Substitute the SRS main harness and check for proper operation. If the problem is corrected, replace SRS main harness and then go to "Verification of Vehicle Repair" procedure.
	▶ Substitute a known-good STPS, and check for proper operation. If the problem is corrected, replace STPS and then go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.

1.	Connect scantool and select "Diagnostic Trouble Codes(DTC)" mode.

2.	Using a scantool, clear the DTC.

3.	Operate the vehicle within DTC Enable conditions in General information.

Are any DTC present ?

	▶ Go to the applicable troubleshooting procedure.
	▶ System is performing to specification at this time.