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P182A




DTC P1824, P182A-P182F, P1838, or P1839

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P1824
- Internal Mode Switch P Circuit High Voltage

DTC P182A
- Internal Mode Switch A Circuit Low Voltage

DTC P182B
- Internal Mode Switch B Circuit Low Voltage

DTC P182C
- Internal Mode Switch B Circuit High Voltage

DTC P182D
- Internal Mode Switch P Circuit Low Voltage

DTC P182E
- Internal Mode Switch-Invalid Range

DTC P182F
- Internal Mode Switch C Circuit High Voltage

DTC P1838
- Internal Mode Switch A Circuit High Voltage

DTC P1839
- Internal Mode Switch C Circuit Low Voltage

Diagnostic Fault Information






Typical Scan Tool Data






Transmission Internal Mode Switch Logic






Circuit/System Description

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.

Conditions for Running the DTC

* No Output Shaft Speed DTCs P0722 or P077B.
* The system voltage is 11-18 V.

P182E
* Vehicle ON greater than 5 seconds.
* The system voltage is 11-18 V.

Conditions for Setting the DTC

Any one or more of the following conditions:

* The IMS signal circuit A, B, or P are Low in Park for greater than 8 seconds.
* The IMS signal circuit A is Low in D for 8 seconds.
* The IMS signal circuit C is High in D for 8 seconds.
* The TCM detects an invalid range from the IMS for 3.25 seconds.
* The IMS signal circuit C is high in D for greater than 8 seconds.
* Park/Neutral Switch equals P/N and the IMS state is not Park or Neutral, or the Park/Neutral switch is not Park or Neutral and the IMS state equals Park or Neutral for 4 seconds.
* Or the automatic transmission manual shift shaft position switch assembly indicates a transitional state for 8 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Diagnostic Aids

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.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Programming and Relearning for scan tool information.

Circuit/System Verification

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 Transmission Internal Mode Switch Logic.
2. Perform the Range Selector Lever Cable Adjustment Range Selector Lever Cable Adjustment procedure to verify proper 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.

Circuit/System Testing

1. Vehicle OFF, remove the control valve body cover. Refer to Control Valve Body Cover Removal 3. 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 ohm 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.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

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

* Manual Shift Shaft Position Switch and Fluid Level Control Valve Removal 5. Manual Shift Shaft Position Switch and Fluid Level Control Valve Removal and Manual Shift Shaft Position Switch and Fluid Level Control Valve Installation 94. Manual Shift Shaft Position Switch and Fluid Level Control Valve Installation for Manual Shift Shaft Position Switch, also called the Internal Mode Switch, replacement.
* Automatic Transmission Wiring Harness and Output Speed Sensor Removal 12. Automatic Transmission Wiring Harness and Output Speed Sensor Removal and Automatic Transmission Wiring Harness and Output Speed Sensor Installation 77. Automatic Transmission Wiring Harness and Output Speed Sensor Installation for Automatic Transmission Control Wiring Extension Harness Assembly replacement.
* Control Module References Programming and Relearning for Control Solenoid Valve Assembly and Transmission Control Module Assembly replacement, programming, and setup.
* Perform the Reset Transmission Adapts Programming and Relearning following all transmission related repairs.

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