B139B
DTC B139B
CIRCUIT DESCRIPTION
The starter/generator control module (SGCM) unit is an electronic device that works in conjunction with the electrical subsystem to efficiently perform DC/DC and DC/AC electrical energy conversion and support vehicle functions. The primary mission of the SGCM unit is to:
- The auxiliary power outlets auxiliary power outlet (APO) function will convert 36-volt DC bus power to 120 volts A/C. If the value of APO mode is OFF, then the APO function will be disabled and the APO Converter/Inverter will not transfer or consume any power.
- The APO output A/C voltage will represent the A/C voltage measured at the output of the APO inverter. This signal will have the following specifications:
- Range 120 volts AC, +5%, -8%, @ 20A
- Frequency 60 Hz +/- 0.25 Hz
- Provide 120 volts AC @60 Hz energy for ON and OFF board electrical equipment.
The following DTCs are for external 120-volt A/C harness failures, excessive current loads or internal system failures within the SGCM.
- B139A Output voltage of the converter is too low to meet current APO mode.
- B139B Value of APO current is less than 60 amps.
- B139C Value of APO current is greater than 60 amps.
- B139E APO commanded ON, but the converter remains OFF.
- B139F APO commanded OFF, but the converter remains ON.
- B140A Internal SGCM circuit to monitor the ground fault detection.
- B140C APO is disabled due to improper DC bus input voltage or excessive internal temperatures.
DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC B139A DC/AC Converter Input Voltage Low
- DTC B139B DC/AC Converter Current Sensor Low
- DTC B139C DC/AC Converter Current Sensor High
- DTC B139D DC/AC Converter Output (single or 1) Current High
- DTC B139E DC/AC Converter Stuck OFF
- DTC B139F DC/AC Converter Stuck ON
- DTC B140A DC/AC Converter Output (single or 1) Ground Fault Performance
- DTC B140B DC/AC Converter Output (single or 1) Ground Fault
- DTC B140C DC/AC Converter Performance
CONDITIONS FOR RUNNING THE DTC
- Engine running for 30 seconds.
- The SGCM has received voltage on the ignition 0 voltage circuit.
- The SGCM has turned ON and no configuration DTC are present.
- This diagnostic will be run every 1.12 ms.
- Reference voltage is stable and accurate.
CONDITIONS FOR SETTING THE DTC
- B139A DC/AC converter input voltage low.
- B139B DC/AC converter current sensor low.
- B139C DC/AC converter current sensor high.
- B139D DC/AC converter output 1 current sensor high.
- B139E DC/AC converter stuck OFF.
- B139F DC/AC converter stuck ON.
- B140A DC/AC converter output 1 ground fault circuit performance.
- B140B DC/AC converter output 1 ground fault detected.
- B140C DC/AC converter performance.
ACTION TAKEN WHEN THE DTC SETS
- The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The driver information center, if equipped, may display a message.
CONDITIONS FOR CLEARING THE DTC
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool.
TEST
