B2101

B2101-IGNITION RUN/START INPUT CIRCUIT LOW





For a complete wiring diagram Consult Diagrams/Electrical.

Theory of Operation

The Occupant Classification Module (OCM) monitors the CAN BUS message containing the battery voltage. If the battery voltage is below 10.0 volts the DTC be set active. The OCM receives operating voltage from the A21 Run/Start circuit by way of the PDC, C6 Fuse, and the F12 Fused Ignition Switch Output Switch Run/Start circuit. If the CAN BUS message containing the battery voltage drops below 10 ±0.25 volts for 3 seconds the DTC be set active.

- When Monitored:
At ignition ON or CAN BUS active, and the CAN BUS is RUN or signal not available, the OCM will monitor the CAN BUS message for battery voltage over 10.0 volts.

- Set Condition:
With the ignition on, and the CAN BUS message contains battery voltage less than 10.0 ±0.25 volts for 3 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Restraints System Pre-Diagnostic Procedure

Diagnostic Test

1. VERIFY OCM COMMUNICATION
NOTE: Ensure the battery is fully charged.

Turn the ignition on.
With the scan tool, read OCM DTC.
Does the scan tool display active: No Response from OCM?

Yes

- Perform LOST COMMUNICATION WITH OCM procedure.Lost Communication With OCM (Gateway Module)

No

- Go To 2

Diagnostic Test

2. VERIFY ACTIVE B2101-IGNITION RUN/START INPUT CIRCUIT LOW.
With the scan tool, read ORC DTC.
Does the scan tool display active: B2101-IGNITION RUN/START INPUT CIRCUIT LOW?

Yes

- Go To 3

No

- Go To *RESTRAINTS SYSTEM INTERMITTENT TEST.Restraints System Intermittent Test

3. VERIFY F12 FUSED IGNITION SWITCH OUTPUT VOLTAGE
WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

With the scan tool, read battery voltage from the PCM.
Is the PCM battery voltage above 10.0 volts?

Yes

WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

- Replace the OCM.
- Perform *OCM REZERO. Restraint System

No

- Repair the low battery or charging system.
- Perform *RESTRAINTS SYSTEM VERIFICATION TEST. Verification Tests.