P182B
DTC P1824, P182A-P182F, P1838, or P1839
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 (IMS) assembly, is a dual sliding contact 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 (HPCM). 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 IMS Range and IMS Direction. The IMS Range input parameters represented are transmission range signal A, signal B, signal C, and signal P. The IMS Direction input parameters represented are transmission direction signal R1, signal R2, signal D1, signal D2, and signal Start.
Conditions for Running the DTC
* No OSS DTCs P0722 or P077B.
* The system voltage is 11-18V.
P182E
* The engine run time is greater than 5 seconds.
* The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.
Conditions for Setting the DTC
P1824
* DTC P1824 has not failed this key cycle.
* The IMS signal circuit P is High in PARK for 3 seconds.
P182A
* DTC P182A has not failed this key cycle.
* The IMS signal circuit A is Low in DRIVE for 8 seconds.
P182B
* DTC P182B has not failed this key cycle.
* The IMS signal circuit B is Low in PARK for 3 seconds.
P182C
* DTC P182C has not failed this key cycle.
* The IMS signal circuit B is High in DRIVE for 9 seconds.
P182D
* DTC P182D has not failed this key cycle.
* The IMS signal circuit P is Low in DRIVE for 9 seconds.
P182E
* DTC P182E has not failed this key cycle.
* The IMS range is invalid for 5 seconds.
P182F
* DTC P182F has not failed this key cycle.
* The IMS signal circuit C is High in DRIVE for 3 seconds.
P1838
* DTC P1838 has not failed this key cycle.
* The IMS signal circuit A is High in PARK for 3 seconds.
P1839
* DTC P1839 has not failed this key cycle.
* The IMS signal circuit C is Low in PARK for 3 seconds.
Action Taken When the DTC Sets
* The TCM commands maximum line pressure.
* The TCM turn OFF all solenoids.
* The TCM freezes transmission adaptive functions.
* The TCM defaults the transmission to 3rd gear if the current gear is 1st or 2nd gear, or 3rd gear if the current gear is 4th gear.
Conditions for Clearing the DTC
DTCs P1824, P182A-P182F, P1838, and P1839 are Type B DTCs.
Diagnostic Aids
The IMS connects electrically to the control solenoid (w/body and TCM) valve assembly and is serviced separately from the control solenoid (w/body and TCM) valve assembly. Inspect the IMS, harness, connector, and control solenoid (w/body and TCM) valve assembly pins for metallic debris. Use a terminal test kit for any test that requires probing the control solenoid (w/body and TCM) valve assembly harness connector or a component harness connector. The IMS assembly can be damaged by currents exceeding 2 mA. Test the IMS 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 (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information.
Circuit/System Verification
Test for the correct operation of the IMS. Refer to Transmission Internal Mode Switch Logic (Transmission Internal Mode Switch Logic).
If the IMS operation matches the IMS logic table, the system if functioning normally.
Circuit/System Testing
Note: Do not connect an external voltage to any control solenoid (w/body and TCM) valve assembly terminal, and avoid the inadvertent shorting of terminals.
1. Ignition OFF, remove the control valve body cover. Refer to Control Valve Lower Body and Upper Body Replacement (2MT70 - Automatic Transmission).
2. Connect the TCM harness connector.
3. Disconnect the IMS connector at the control solenoid (w/body and TCM) valve assembly.
4. Ignition ON, verify the scan tool IMS A/B/C/P parameter displays HI for all four signal circuits.
• If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
5. Connect a 3-amp fused jumper wire between each transmission range signal circuit terminal listed below and the IMS ground circuit, terminal A. The appropriate scan tool IMS A/B/C/P parameter should display LOW when the terminal is connected to the IMS ground.
* Switch Signal A terminal E
* Switch Signal B terminal D
* Switch Signal C terminal C
* Switch Signal P terminal B
• If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
6. If all circuits test normal, test or replace the IMS.
Component Testing
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 (Overhaul) and Manual Shift Shaft Position Switch and Fluid Level Control Valve Installation (Overhaul) for IMS replacement.
* Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.
* Automatic Transmission Wiring Harness and Output Speed Sensor Removal (Overhaul) and Automatic Transmission Wiring Harness and Output Speed Sensor Installation (Overhaul) for automatic transmission control wiring harness extension harness assembly replacement.