Loss Of Ignition Run Start
LOSS OF IGNITION RUN - START
For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.
Theory of Operation
The Occupant Restraint Controller module (ORC) receives power from both a run/start and run only ignition supply circuits. These circuits power the ORC and the capacitors used to initiate the squib deployment circuits in the event of collision detection. The OCM A21 Run/Start circuit provides battery voltage to the PDC C6 Fuse and the F12 Fused Ignition Switch Output Switch Run/Start circuit. If the voltage on the Fused Ignition Switch Output Run/Start circuit is below 6.0 volt the DTC will be set active.
- When Monitored:
With the ignition in the Run-Start position.
- Set Condition:
The Occupant Restraint Controller (ORC) monitors the voltage of the (F12) Fused Ignition Switch Output (Run-Start) circuit and will set this DTC if it drops below approximately 6.0 ± 0.25 volts.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure.
1. VERIFY THAT ACTIVE LOSS OF IGNITION RUN - START DTC
NOTE: Ensure that the battery is fully charged.
1. Turn the ignition on.
2. With the scan tool, read the active ORC DTC.
Does the scan tool display active ORC DTC: LOSS OF IGNITION RUN - START
Yes
- Go To 2
No
- Perform the RESTRAINTS SYSTEM INTERMITTENT TEST. Restraints System Intermittent Test.
2. VERIFY ACTIVE B2101-IGNITION RUN/START INPUT CIRCUIT LOW DTC.
1. With the scan tool, read OCM DTC.
Does the scan tool display an active: B2101-IGNITION RUN/START INPUT CIRCUIT LOW OCM DTC?
Yes
- Go To 3
No
- Go To 9
3. INSPECT AIRBAG RUN-START FUSE
1. Turn the ignition off.
2. Remove the PDC C6 Fuse and inspect the fuse.
NOTE: Check connectors - Clean and repair as necessary.
Is the fuse open?
Yes
- Go To 4
No
- Go To 7
4. CHECK (F12) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE
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. Measure the resistance of the (F12) Fused Ignition Switch Output (Run-Start) circuit between the PDC C6 Fuse terminal (output side) and ground.
Is the resistance below 100.0 ohms?
Yes
- Go To 5
No
- Using the wiring diagram/schematic as a guide, inspect the related wiring and connectors. Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
- Replace PDC C6 Fuse.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
5. CHECK (F12) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE WITH OCM CONNECTOR DISCONNECTED
1. Disconnect the OCM C1 connector.
NOTE: Check connectors - Clean and repair as necessary.
2. Measure the resistance of the (F12) Fused Ignition Switch Output (Run-Start) circuit between the PDC C6 Fuse terminal (output side) and ground.
Is the resistance below 100.0 ohms?
Yes
- Go To 6
No
- WARNING: If the Occupant Classification Module is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental airbag deployment and serious or fatal injury.
- Replace the OCM.
- Replace the PDC C6 Fuse.
- Perform the OCM REZERO. Testing and Inspection.
6. CHECK (F12) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT RESISTANCE WITH ORC AND OCM CONNECTORS DISCONNECTED
1. Disconnect the ORC connectors.
NOTE: Check connectors - Clean and repair as necessary.
2. Measure the resistance of the (F12) Fused Ignition Switch Output (Run-Start) circuit between the PDC C6 Fuse terminal (output side) and ground.
Is the resistance below 100.0 ohms?
Yes
- Repair the (F12) Fused Ignition Switch Output (Run-Start) circuit short to ground.
- Replace the PDC C6 Fuse.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- WARNING: If the Occupant Restraint Controller is dropped at any time, it must be replaced. Failure to take the proper precautions can result in accidental airbag deployment and serious or fatal injury.
- Replace the ORC.
- Replace the PDC C6 Fuse.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
7. CHECK (A21) IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN
1. Turn the ignition on.
2. Measure the voltage of the (A21) Ignition Switch Output (Run-Start) circuit at the PDC C6 Fuse terminal (supply side).
Is the voltage above 6.0 ± 0.25 volts?
Yes
- Go To 8
No
- Repair the open or high resistance in the Airbag Run-Start Fuse C6 (A21) Ignition Switch Output Run/Start supply circuit (input side).
- Reinstall the PDC C6 Fuse.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
8. CHECK THE (F12) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN
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 ORC connectors.
NOTE: Check connectors - Clean and repair as necessary.
NOTE: If not done so previously, reinstall the Airbag Run-Start circuit fuse.
2. Connect the Load Tool ORC 8443-25 Adaptor to the ORC connectors.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
3. Measure the voltage of the (F12) Fused Ignition Switch Output (Run-Start) circuit between the ORC 8443-25 Adaptor cavity 32 way-17 and ground.
Is the voltage above 6.0 ± 0.25 volts?
Yes
- 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.
- WARNING: If the Occupant Restraint Controller is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and serious or fatal injury.
- Replace the ORC.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- Repair the open or high resistance in the (F12) Fused Ignition Switch Output (Run-Start) circuit.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
9. CHECK (F12) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN
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. Reconnect the PDC C6 Fuse if previously disconnected.
2. Disconnect the ORC connectors.
NOTE: Check connectors - Clean and repair as necessary.
3. Connect the Load Tool ORC 8443-25 Adaptor to the ORC connectors.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
4. Measure the voltage of the (F12) Fused Ignition Switch Output (Run-Start) circuit between the ORC 8443-25 Adaptor cavity 32 way-17 and ground.
Is the voltage above 6.0 ± 0.25 volts?
Yes
- 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.
- WARNING: If the Occupant Restraint Controller is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and serious or fatal injury.
- Replace the ORC.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.
No
- Repair the open (F12) Fused Ignition Switch Output (Run-Start) circuit between the ORC splice and the OCM.
- Perform the RESTRAINTS SYSTEM VERIFICATION TEST. Restraints System Verification Test.