Volt

DTC P181C-P181F, P183A-P183E, P184A, or P184B

The automatic transmission manual shift shaft position switch assembly, also called the internal mode switch assembly, contains two sliding hall-effect switch assemblies attached to the control valve body within the transmission. The 9 outputs from the switches indicate which position is selected by the transmission manual shaft. Four outputs (A, B, C, P) are range selection inputs to the transmission control module (TCM). Five outputs (R1, R2, D1, D2, S) are direction selection inputs to the hybrid powertrain control module. The Range input signals are represented as TCM scan tool parameters, Internal Mode Switch A, B, C, and P. The Direction input signals are represented as hybrid powertrain control module scan tool parameters, Internal Mode Switch 2 - R1, R2, D1, D2, and S. The input voltage at the modules is high when a switch is open and low when a switch is closed to earth. Each control module independently supplies power and earth to its respective switch assembly.

The hybrid powertrain control module is internal to the power inverter module, often referred to as the drive motor generator power inverter module and is not serviced separately.

The direction internal mode switch state does not match a selected gear for 5 seconds.

DTCs P181C, P181D, P181E, P181F, P183A, P183B, P183C, P183D, P183E, P184A and P184B are Type B DTCs.

DTCs P181C, P181D, P181E, P181F, P183A, P183B, P183C, P183D, P183E, P184A and P184B are Type B DTCs.

Schematic Reference

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

DT-44152 Jumper Harness

For equivalent regional tools, refer to Special Tools .

Vehicle ON, observe the scan tool internal mode switch 2 parameters while moving the gear shift lever from Park, through all gear selector positions, and back to Park. The parameters should match each gear range that is selected. Refer to Internal Mode Switch 2 Parameters table below:

1. Vehicle OFF. Disconnect the X175 20-way harness connector at the transmission. Additional DTCs may set.
2. Install the DT-44152 jumper harness to the harness side only.
3. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 Ω between the low reference circuit terminal G and earth.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the T6 power inverter module.

4. Vehicle ON, verify that each scan tool D1/D2/R1/R2/S parameter displays high.

⇒	If any parameter displays low, test that signal circuit terminal, as listed below, for a short-circuit to earth. If the circuit tests normal, replace the T6 power inverter module.

•	Parameter D1 - terminal E

•	Parameter D2 - terminal F

•	Parameter R1 - terminal C

•	Parameter R2 - terminal D

•	Parameter S - terminal B

5. Install a 3 A fused jumper wire between each terminal listed below, one at a time, and earth. Verify that each scan tool D1/D2/R1/R2/S parameter displays low when earthed.

⇒	If a parameter displays high when earthed, test that signal circuit terminal, as listed below, for a short to voltage or an open/high resistance. If the circuit tests normal, replace the T6 power inverter module.

•	Parameter D1 - terminal E

•	Parameter D2 - terminal F

•	Parameter R1 - terminal C

•	Parameter R2 - terminal D

•	Parameter S - terminal B

6. If the circuits test normal, test or replace the transmission internal extension harness or the automatic transmission B15 internal mode switch.

Perform the Diagnostic Repair Verification after completing the repair.