DTC B1760, "Occupant Detection Sensor Mat" New Troubleshooting Information (07-134-18)

DTC B1760, "OCCUPANT DETECTION SENSOR MAT" NEW TROUBLESHOOTING INFORMATION

TECHNICAL SERVICE BULLETIN

APPLICABILITY

2012-2016MY Impreza

2013-2017MY Crosstrek

2015-2018MY WRX

INTRODUCTION

This Service Information bulletin provides a new troubleshooting chart to use when diagnosing a DTC B1760 related to the Occupant Detection System (ODS). Following these diagnostic steps will help avoid unnecessary ODS sensor / seat cushion assembly replacement.

SERVICE PROCEDURE / INFORMATION

VERY IMPORTANT  : BEFORE proceeding with diagnosis of any ODS-related DTC, always check to see (feel) if the seat cushion is wet, contains any moisture or, if the vehicle has been used under excessively humid conditions as the Airbag system may detect DTC B1760 and illuminate the airbag warning light.

In most cases, this condition can be remedied by thoroughly drying the seat cushion assembly. 

• If any moisture is confirmed, the cushion must be completely  dried, see the DRYING PROCEDURES  section supplied later in this bulletin.
• It is VERY IMPORTANT to understand the occupant detection sensor mat is a sensitive component. For that reason, NEVER  use a heat gun or a hair dryer in an attempt to "force dry" the seat cushion before proceeding with further troubleshooting.

A "temporarily" wet seat cushion resulting from (as examples) a window being inadvertently left open during rainfall or possibly spilled food / drink with a resulting clean-up using water and / or cleaning liquids can cause moisture to be left behind and B1760 (or a related DTC) to set. This is the most common scenario and what can easily lead to an unnecessary seat cushion replacement. 

It is VERY IMPORTANT  to thoroughly review this information with the customer during the Service write-up interview. Attempt to determine if this is an actual concern with the system or if outside influence (moisture) may well be the root cause of the condition BEFORE proceeding with further diagnosis or ordering any parts. Use the Owner's Manual wording as an additional reference for any discussions with the customer. If the memory is cleared and the seat cushion is not thoroughly dry, the code will likely reset once someone sits in the seat again. In this case, the system is operating as designed (unless there is a damaged component or poor harness connection confirmed as causing the DTC).

If the passengers' seat cushion is found wet or displays any staining, dry the seat cushion completely using natural air. Parking the vehicle in a sunny spot with windows slightly open is recommended.

To speed the drying time, it is recommended to use the vehicle's Air Conditioner function:

• Park the vehicle in open area or use exhaust ventilation equipment
• Set the parking brake and start the engine
• Turn the A/C ON, set the blower fan to MAX, then direct airflow from the vents at the seat cushion
• Set A/C temperature to a comfortable room temperature (full heat is not required).

Once moisture has been ruled out as a possible cause of the DTC, proceed with the remaining diagnostic steps below (starting with Step 3  ).

Step	Check	Yes	No
1 CHECK AIRBAG WARNING LIGHT.  Check the airbag warning light illuminate or not.	Does it illuminate?	Go to step 2.	Read the DTC, and if DTC B1760 is recorded as a past malfunction. Go to step 3.
2 CHECK STATUS OF PASSENGER'S SEAT.  Check if the passengers seat cushion is wet.	Is it wet?	Go to step 3.	Go to step 6.
3 DRY PASSENGER'S SEAT.  Dry the passenger's seat well naturally	Is it dry?	Go to step 4.	After drying well, Go to step 4.
4 CHECK DTC.  Read the DTC of the occupant detection system. <Ref. to OD(diag)-1G. OCCUPANT DETECTION SYSTEM, OPERATION, Read Diagnostic Trouble Code (DTC)>	Is current DTC B17G0 displayed again?	When DTC B1760 is displayed again. Go to step 5.	Clear the memory. <Ref to OD(diag)-21. OCCUPANT DETECTION SYSTEM, OPERATION, Clear Memory Mode.>
5 CHECK POOR CONTAC T OF CONNECTORS.  Check for poor contact of connectors between the occupant detection control module and the occupant detection sensor.	Is there poor contact of connector?	When the connector is not fully connected, reconnect the connector correctly. Replace the faulty harness if the connector is faulty. (Replace the occupant detection harness or replace the occupant detection system (passengers & frame assembly)). <Ref. to SE-28. PASSENGER'S SEAT, DISASSEMBLE, Front Seat>	Replace the occupant detection system (passengers & frame assembly)). <Ref. to SE-28, PASSENGER'S SEAT, DISASSEMBLE, Front Seat>
6. CHECK POOR CONTACT OF CONNECTORS.  Check for poor contact of connectors between the occupant detection control module and the occupant detection sensor.	Is there poor contact of connector?	When the connector is not fully connected, reconnect the connector correctly. Replace the faulty harness if the connector is faulty. (Replace the occupant detection harness or replace the occupant detection system (passengers & frame assembly)). <Ref. to SE-28. PASSENGER'S SEAT, DISASSEMBLE, Front Seat>	After drying well, Go to step 7.
7 CHECK DTC.  Read the DTC of the occupant detection system. <Ref. to OD(diag)-19. OCCUPANT DETECTION SYSTEM, OPERATION, Read Diagnostic Trouble Code (DTC)>	Is current DTC B1760 displayed again?	Replace the occupant detection harness or replace the occupant detection system (passengers & frame assembly). <Ref. to SE-28. PASSENGER'S SEAT, DISASSEMBLE, Front Seat >	Clear the memory. <Ref to OD(diag)-21. OCCUPANT DETECTION SYSTEM, OPERATION, Clear Memory Mode>

WARRANTY / CLAIM INFORMATION

Refer to the Labor Time Guide on Subarunet for applicable claim coding information.

IMPORTANT REMINDERS: 

• SOA strongly discourages the printing and/or local storage of service information as previously released information and electronic publications may be updated at any time.
• Always check for any open recalls or campaigns anytime a vehicle is in for servicing.
• Always refer to STIS for the latest service information before performing any repairs.