Volt

DTC P1824, P182A-P182F, P1838, or P1839

The automatic transmission manual shift shaft position switch assembly, also called the internal mode switch assembly, is a dual sliding hall-effect switch attached to the control valve body within the transmission. The 9 outputs from the switch 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 input voltage at the modules is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as Internal Mode Switch A/B/C/P and Internal Mode Switch Status D1/D2/R1/R2/S. The Internal Mode Switch Range input parameters represented are transmission range signal A, signal B, signal C, and signal P. The Internal Mode Switch Direction input parameters represented as Internal Mode Switch Status signal R1, signal R2, signal D1, signal D2, and signal Start.

P182E

Any one or more of the following conditions:

The PRNDL position indicator on the instrument cluster will be blank.

DTCs P1824, P182A-P182F, P1838, and P1839 are Type B DTCs.

The automatic transmission manual shift shaft position switch assembly connects electrically to the control solenoid valve assembly. Inspect the automatic transmission manual shift shaft position switch, harness, connector, and control solenoid assembly pins for metallic debris. Use a terminal test kit for any test that requires probing the control solenoid assembly harness connector or a component harness connector. The automatic transmission manual shift shaft position switch assembly can be damaged by currents exceeding 2 mA. Test the automatic transmission manual shift shaft position switch assembly for an open condition whenever a short to voltage condition is observed.

Schematic Reference

Automatic Transmission Controls Schematics

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.

1. Vehicle ON, observe the scan tool Internal Mode Switch A/B/C/P parameter while moving the gear shift lever from Park, through all gear selector positions, and back to Park. The parameter should match each gear range that is selected. Refer to Transmission Internal Mode Switch Logic .
2. Perform the Range Selector Lever Cable Adjustment procedure to verify correct adjustment.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Vehicle OFF, remove the control valve body cover. Refer to Control Valve Body Cover Removal .
2. Vehicle OFF, disconnect the X2 harness connector at the B15 Transmission Internal Mode Switch.
3. Vehicle OFF, all systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10.0 Ω between the ground circuit terminal 7 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the Q8 control solenoid assembly.

4. Vehicle ON, Verify the scan tool Internal Mode Switch A/B/C/P parameter displays HI for all four signal circuits.

⇒	If not the specified value, test the signal circuits for a short to ground or short together. If the circuits test normal, replace the Q8 control solenoid valve assembly.

5. Vehicle ON, test for 9.6-12.5V between the voltage circuit terminal 2 and terminal 7.

⇒	If not within the specified range, test the voltage circuit for an open/high resistance. If the circuit tests normal, replace the Q8 control solenoid assembly.

6. Vehicle ON, Install a 3 A fused jumper wire between each signal circuit listed below and the ground circuit terminal 7. Verify the scan tool Internal Mode Switch A/B/C/P parameter is Low:

•	Switch Signal A: terminal 6 to terminal 7

•	Switch Signal B: terminal 5 to terminal 7

•	Switch Signal C: terminal 4 to terminal 7

•	Switch Signal P: terminal 3 to terminal 7

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the Q8 control solenoid assembly.

7. If all circuits test normal, replace the B15 Transmission Internal Mode Switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Note: Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection for the following components before replacing the components.