B274C-2B
B274C-2B-DRIVER SIDE SEAT THORAX SQUIB 1 CONTROL - WIRES SHORTED TOGETHER
Special Tools:
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
When powered, the Occupant Restraint Controller (ORC) sends a test current to the squibs to verify the integrity of the squib and the wiring. These circuits are maintained in a "floating" configuration at the module, (connected to neither power nor ground), as protection against inadvertent deployment. Use of the SRS Load Tool in the tests below, substitutes a suspect squib with a known good component. (8443A)The use of the SRS Load Tool Adapter provides a test point, as well as a method for opening the shorting bar connections within the harness connector. (8443-57)
- When Monitored:
Voltage must be in the normal range and the squib is configured for the ORC to test the circuit. The ORC sends out a 40 mA diagnostic current on each squib voltage supply circuit at power up and every 400 ms thereafter while the ignition is in on. The module then monitors the return wire to determine the state of the circuit.
- Set Condition:
This DTC sets when the ORC detects the squib circuits shorted together for more than 2.5 seconds. This DTC transitions from active to stored when the module sees a recovery from a short to ground for greater than 2.5 seconds. The stored condition will be cleared if the condition does not return within 100 key cycles.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure.
Diagnostic Test
1. DETERMINE ACTIVE OR STORED DTC
NOTE: Make sure the battery is fully charged.
1. Turn the ignition on.
2. With the scan tool, read all active ORC DTCs.
Is the DTC active or stored?
ACTIVE DTC
- Go To 2.
STORED DTC
- Perform the RESTRAINTS SYSTEM INTERMITTENT TEST. Restraints System Intermittent Condition Test.
2. CHECK FOR SHORTED SQUIB CIRCUITS IN THE LEFT SEAT THORAX AIRBAG
WARNING:
Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
1. Disconnect the Left Seat Thorax Airbag connector.
WARNING:
Do not place an intact undeployed airbag face down on a hard surface, the airbag will propel into the air if accidentally deployed. Failure to follow these instructions may result in possible serious or fatal injury.
NOTE: Check the connectors - Clean and repair as necessary.
2. Connect the SRS Load Tool and the SRS Load Jumper to the Left Seat Thorax Airbag connector. (8443A) (8443-8)
WARNING:
Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
3. With the scan tool, read the active ORC DTCs.
Does the scan tool display: B274C-2B-LEFT SIDE THORAX SQUIB 1-WIRES SHORTED TOGETHER?
Yes
- Go To 3.
No
WARNING:
Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
Replace the Left Seat Airbag.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
3. CHECK (R7) LEFT SEAT THORAX SQUIB 1 LINE 1 CIRCUIT FOR A SHORT TO (R5) LEFT SEAT THORAX SQUIB 1 LINE 2 CIRCUIT
WARNING:
Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
1. Disconnect the SRS Load Tool and the SRS Load Jumper. (8443A) (8443-8)
2. Disconnect the ORC C1 and C2 connectors.
NOTE: Check the connectors - Clean and repair as necessary.
3. Connect the SRS Load Tool Adapter to the ORC C1 and C2 harness connectors. (8443-57)
4. Measure the resistance between the (R7) Left Seat Thorax Squib 1 Line 1 circuit and the (R5) Left Seat Thorax Squib 1 Line 2 circuit between the SRS Load Tool Adapter cavity C1B-15 and C1B-16. (8443-57)
Is the resistance below 5k Ohms?
Yes
- Repair or replace the (R7) Left Seat Thorax Squib 1 Line 1 circuit for a short to the (R5) Left Seat Thorax Squib 1 Line 2 circuit.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
WARNING:
If the Occupant Restraint Controller (ORC) is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental airbag deployment. Failure to follow these instructions may result in possible serious or fatal injury.
- Replace the ORC module. Occupant Restraint Controller - Removal
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.