Solenoid valve for stage 3 - Open circuit
Check high voltage side cable harness on the solenoid valve actuator box and on the G6 ECU. If a fault code for stage4 gear also indicating open circuit check the low voltage connection on the cable harness for the solenoid valve actuator box and for the G6 ECU. Check the wire between G6 ECU and the solenoid valve actuator box. The fault can also be inside the solenoid valve actuator box.
What you'll see
No driver-visible symptom recorded.
System reaction
The system will not be able to shift the stage3/stage4 gear sleeve. If the stage3/stage4 gear sleeve is engaged, it will be possible to continue in the current gear. If the stage3/stage4 gear sleeve is not engaged, no gears will be available.
Diagnostic depth
Solenoid valve is disconnected either on the high or the low voltage side. If disconnected on the low voltage side the solenoid valve for stage4 gear will also have an open circuit fault code.
Harness, connectors or component has open circuit.