Pinpoint Tests AA: DTCs B2290 and C1941

Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)

Pinpoint Test AA: DTCs B2290 and C1941

Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number

Normal Operation

The Occupant Classification System Module (OCSM) monitors the pressure sensor and circuity for faults. If a fault is detected, the OCSM stores DTC B2290 in memory and sends a message to the Restraints Control Module (RCM). The RCM stores DTC B00A0:09 in memory and sends a message to the Instrument Panel Cluster (IPC) to illuminate the air bag warning indicator.

The Occupant Classification System (OCS) system components are not to be serviced separately.

DTC C1941 sets when system reset fails to complete the testing. DTC C1941 clears upon a successful system reset.

a Fault PIDs that end in OD indicate on-demand status and are associated with DTC B2290. Fault PIDs that end in CM indicate continuous memory status and are associated with DTC B2290.

- DTC C1941 (Zero Seat Weight Test Failure) - This DTC sets if the OCSM is unable to complete a successful System Reset. All other OCS system DTCs must be diagnosed and repaired before carrying out the OCS system reset.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Faulty OCS system component
- Pressure sensing fault
- Mounting condition

PINPOINT TEST AA: DTCs B2290 AND C1941

WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

WARNING: Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners, adaptive load limiting retractors, or safety belt inflators, which increases the risk of serious personal injury or death.

NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Inspection and Verification

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

NOTE: Only disconnect or reconnect Supplemental Restraint System (SRS) components when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.

NOTE: A production OCS system allows the disconnect of the electrical connector from the OCSM.

An OCS system service kit has the OCSM electrical connector glued to the module. It cannot and should not be disconnected or altered.

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AA1 RETRIEVE OCSM DTCs

- Enter the following diagnostic mode on the scan tool: Self Test - OCSM.
- Enter the following diagnostic mode on the scan tool: DataLogger - OCSM - View and Record All 2290 Fault PIDs.
- Refer to PID list in Normal Operation to view 2290 fault PIDs.
- Do any on-demand 2290 fault PIDs indicate a fault and/or was DTC C1941 retrieved during self-test?

Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test.

GO to AA2.

No
This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to AA13.

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AA2 CHECK THE SEAT WIRING AND CONNECTORS

- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Carry out a thorough inspection of the OCS system wiring, terminals and connectors and the related seat wiring harness and body wiring harness terminals and connectors.
- Were any problems noted?

Yes
DEPOWER the SRS and REPAIR the seat connectors and wiring as needed. GO to AA14.

If DTC C1941 was present, GO to AA9.

If DTC C1941 was not present, GO to AA14.

No
Vehicles with a production OCS system:

For DTC C1941, GO to AA9.

For fault PID 2290_15_OD, GO to AA3.

For fault PID 2290_13_OD, GO to AA10.

For fault PID 2290_12_OD, GO to AA11. Vehicles with a OCS system service kit, INSTALL a new OCS system service kit. REFER to Occupant Classification Sensor Service and Repair. GO to AA14.

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AA3 CHECK THE OCS PRESSURE SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

- Depower the Supplemental Restraint System (SRS). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C337.
- Disconnect: Seat Pressure Sensor C3042.
- Disconnect: OCSM C3159.
- Ignition ON.
- Measure the voltage between seat pressure sensor:
- C3042-1, circuit CR152 (GY/YE), harness side and ground.
- C3042-2, circuit VR223 (BU/WH), harness side and ground.
- C3042-3, circuit RR152 (YE/VT), harness side and ground.

- Are the resistances greater than 10,000 ohms?

Yes
GO to AA5.

No
REPAIR circuit CR152 (GY/YE), RR152 (YE/VT) or VR223 (BU/WH).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA5 CHECK THE SEAT PRESSURE SENSOR CIRCUIT VREF FOR AN OPEN

- Measure the resistance between OCSM C3159-3, circuit CR152 (GY/YE), harness side, and seat pressure sensor C3042-1, circuit CR152 (GY/YE), harness side.

- Is the resistance less than 0.5 ohm?

Yes
GO to AA6.

No
REPAIR circuit CR152 (GY/YE).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA6 CHECK THE SEAT PRESSURE SENSOR RETURN CIRCUIT FOR AN OPEN

- Measure the resistance between OCSM C3159-5, circuit RR152 (YE/VT), harness side, and seat pressure sensor C3042-3, circuit RR152 (YE/VT), harness side.

- Is the resistance less than 0.5 ohm?

Yes
GO to AA7.

No
REPAIR circuit RR152 (YE/VT).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA7 CHECK THE SEAT PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN

- Measure the resistance between OCSM C3159-4, circuit VR223 (BU/WH), harness side, and seat pressure sensor C3042-2, circuit VR223 (BU/WH), harness side.

- Is the resistance less than 0.5 ohm?

Yes
GO to AA8.

No
REPAIR circuit VR223 (BU/WH).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA8 CHECK FOR A SHORT BETWEEN SEAT PRESSURE SENSOR CIRCUITS

- Measure the resistance between seat pressure sensor:
- C3042-1, circuit CR152 (GY/YE), harness side, and C3042-2, circuit VR223 (BU/WH), harness side.
- C3042-1, circuit CR152 (GY/YE), harness side, and C3042-3, circuit RR152 (YE/VT), harness side.
- C3042-2, circuit VR223 (BU/WH), harness side, and C3042-3, circuit RR152 (YE/VT), harness side.

- Are the resistances greater than 10,000 ohms?

Yes
INSTALL a new OCS system service kit. REFER to Occupant Classification Sensor Service and Repair. GO to AA14.

No
REPAIR circuit CR152 (GY/YE), RR152 (YE/VT) and/or VR223 (BU/WH).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA9 CHECK THE OCS SYSTEM

NOTE: Make sure all OCS system components, SRS components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out self-test. If not, DTCs will be recorded.

- Enter the following diagnostic mode on the scan tool: OCS System Reset.
- WARNING: Make sure the front passenger seat repair is complete, the seat and all attached components (head restraint, seat side shield, etc.) are correctly assembled, and the seat is correctly installed to the vehicle before carrying out the System Reset. Failure to follow these instructions may result in incorrect operation of the occupant classification system (OCS) and increases the risk of serious personal injury or death in a crash.
- NOTICE: To prevent system failure, take the following precautions before carrying out the Occupant Classification System (OCS) system reset:
- Make sure the OCS system components are connected and no Occupant Classification System Module (OCSM) faults are present, with the exception of DTC C1941. All other OCS system DTCs must be diagnosed and repaired before carrying out the OCS system reset.
- Make sure the voltage to the OCSM is greater than 8 volts and less than 18 volts.
- Make sure the OCS system is not at a temperature below 6°C (42°F) or above 36°C (97°F) when initiating the OCS system reset process. If the vehicle has been exposed to extreme cold or hot temperatures, the vehicle must be exposed and kept at a temperature within the limits, 6°C to 36°C (42°F to 97°F) for a minimum of 30 minutes.
- Make sure nothing is present on the passenger seat before carrying out the OCS system reset and nothing is placed on the seat during the process.
- Make sure a minimum 8-second time period has passed after cycling the ignition switch ON before the carrying out the OCS system reset process.

- Carry out the OCS system reset.
- If the first system reset attempt was unsuccessful, carry out a thorough inspection of the following and repair any concerns found.

- OCS system connector and wiring for damage
- Pressure sensor hose for kinks and/or damage
- Seat-related wiring harness and body wiring harness terminals and connectors for damage
- Carry out a second OCS system reset. If the second attempt is unsuccessful, install a new OCS system service kit. Refer to Occupant Classification Sensor Service and Repair.
- Ignition OFF.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - OCSM.
- Enter the following diagnostic mode on the scan tool: DataLogger - OCSM - View and Record All 2290 Fault PIDs.
- Refer to PID list in Normal Operation to view 2290 fault PIDs.
- Do any on-demand 2290 fault PIDs indicate a fault and/or was DTC C1941 retrieved on-demand during self-test?

Yes
GO to AA12.

No
Fault corrected. GO to AA14.

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AA10 CHECK THE SEAT PRESSURE SENSOR CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Disconnect: Seat Pressure Sensor C3042.
- Disconnect: OCSM C3159.
- Measure the resistance between seat pressure sensor:
- C3042-1, circuit CR152 (GY/YE), harness side and ground.
- C3042-2, circuit VR223 (BU/WH), harness side and ground.
- C3042-3, circuit RR152 (YE/VT), harness side and ground.

- Are the resistances greater than 10,000 ohms?

Yes
GO to AA12.

No
REPAIR circuit CR152 (GY/YE), RR152 (YE/VT) or VR223 (BU/WH).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

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AA11 CHECK THE SEAT PRESSURE SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Seat Side Air Bag Module C337.
- Disconnect: Seat Pressure Sensor C3042.
- Disconnect: OCSM C3159.
- Repower the SRS. Do not prove out the system at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure the voltage between seat pressure sensor:
- C3042-1, circuit CR152 (GY/YE), harness side and ground.
- C3042-2, circuit VR223 (BU/WH), harness side and ground.
- C3042-3, circuit RR152 (YE/VT), harness side and ground.

- Is any voltage present on any circuit?

Yes
REPAIR circuit CR152 (GY/YE), RR152 (YE/VT) or VR223 (BU/WH).

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

GO to AA14. Diagrams By Number

No
GO to AA12.

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AA12 CONFIRM THE OCS FAULT

NOTE: Make sure all OCS system components, SRS components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out self-test. If not, DTCs will be recorded.

- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Prior to reconnecting any previously disconnected SRS component:

- OCS system connector and wiring for damage.
- pressure sensor hose for kinks and/or damage.
- seat-related wiring harness and body wiring harness terminals and connectors for damage.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- inspect connector(s) (including any in-line connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- repair any concerns found.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

- Connect: OCSM C3159 (if disconnected previously).
- Connect: Seat Pressure Sensor C3042 (if previously disconnected).
- Enter the following diagnostic mode on the scan tool: Self Test - OCSM.
- Enter the following diagnostic mode on the scan tool: DataLogger - OCSM - View and Record All 2290 Fault PIDs.
- Refer to PID list in Normal Operation to view 2290 fault PIDs.
- Does the original on-demand 2290 fault PID indicate a fault or was DTC C1941 retrieved on-demand during self-test?

Yes
INSTALL a new OCS system service kit. REFER to Occupant Classification Sensor Service and Repair. GO to AA14.

No
In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test. GO to AA13.

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AA13 CHECK FOR AN INTERMITTENT FAULT

- Enter the following diagnostic mode on the scan tool: Self Test - OCSM.
- Enter the following diagnostic mode on the scan tool: DataLogger - OCSM - View and Record All 2290 Fault PIDs.
- Do any on-demand 2290 fault PIDs indicate a fault?

Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test.

CHECK for causes of the intermittent fault at or near the affected SRS component connector. REPAIR any intermittent wiring, terminal or connector concerns found.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

If an intermittent concern was found and repaired, GO to AA14.

If an intermittent concern was not found and repaired, USE the fault PIDs recorded and GO to the appropriate pinpoint test step.

Vehicles with a production OCS system

For fault PID 2290_15_OD, GO to AA3.

For fault PID 2290_13_OD, GO to AA10.

For fault PID 2290_12_OD, GO to AA11.

Vehicles with an OCS system service kit:

INSPECT the seat wiring harness for damage and REPAIR as needed.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information.

If OK, INSTALL a new OCS system service kit. REFER to Occupant Classification Sensor Service and Repair. GO to AA11. Diagrams By Number

No

CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition frequently. ACTIVATE other systems in the same wire harness. Do not install any new SRS components at this time. Install SRS components only when directed to do so in the pinpoint test. GO to AA14.

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AA14 CHECK FOR ADDITIONAL SRS DTCs

- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Reconnect all SRS components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - Restraints.
- NOTE: When selecting Restraints from the Self Test menu, DTCs are retrieved from the RCM and OCSM.
- Are any RCM and/or OCSM DTCs retrieved on-demand during self test?

Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the DTC Charts for pinpoint test direction. [1][2]Diagnostic Trouble Code Descriptions

No
CLEAR all RCM and OCSM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

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