DTC P1824, P182A-P182F, P1838, or P1839. Chevrolet Captiva Sport 2009

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2009 🢒 Captiva Sport 🢒 Transmission 🢒 Automatic Transmission - 2MT70 🢒 DTC P1824, P182A-P182F, P1838, or P1839

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

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

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Transmission Range Signal A	P182A	P1838	P1838	P182E
Transmission Range Signal B	P182B	P182C	P182C	P182E
Transmission Range Signal C	P1839	P182F	P182F	P182E
Transmission Range Signal P	P182D	P1824	P1824	P182E
Ground	--	P182A, P182C, P182F, P1838	--	P182E

Typical Scan Tool Data

IMS A/B/C/P

Circuit	Normal Range	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON, range selector in Park
Transmission Range Signal A	LOW	LOW	HI	HI
Transmission Range Signal B	HI	LOW	HI	HI
Transmission Range Signal C	HI	LOW	HI	HI
Transmission Range Signal P	LOW	LOW	HI	HI
HI = 12 volts LOW = 0 volts

Transmission Internal Mode Switch Logic

Gear Selector Position	Signal A	Signal B	Signal C	Signal P
Park (P)	LOW	HI	HI	LOW
Reverse (R)	LOW	LOW	HI	HI
Neutral (N)	HI	LOW	HI	LOW
Drive (D)	HI	LOW	LOW	HI
Manual (M)	HI	HI	LOW	LOW

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 11-18 volts.

P182E

•	The engine run time is greater than 5 seconds.

•	The system voltage is 11-18 volts.

•	The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.

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 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

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

Test for the correct operation of the IMS. Refer to Transmission Internal Mode Switch Logic.

⇒	If the IMS operation matches the IMS logic table, the system if functioning normally.

Circuit/System Testing

Disconnect the IMS harness connector at the control solenoid (w/body and TCM) valve assembly. Ignition ON. The scan tool IMS A/B/C/P parameter should display HI for all 4 signal circuits.

⇒	If a signal circuit displays LOW, replace the control solenoid (w/body and TCM) valve assembly.

Connect a 3-amp fused jumper wire between each transmission range signal circuit at the control solenoid (w/body and TCM) valve assembly and ground. With a scan tool, ensure that each signal circuit displays LOW when connected to ground.

⇒	If a signal circuit remains HI when connected to ground, replace the control solenoid (w/body and TCM) valve assembly.

Connect the IMS harness connector to the control solenoid (w/body and TCM) valve assembly. Disconnect the IMS connector. The scan tool IMS A/B/C/P parameter should display HI for all 4 signal circuits.

⇒	If a signal circuit displays LOW, replace the IMS jumper harness.

Connect a 3-amp fused jumper wire between each transmission range signal circuit at the IMS connector harness and ground. With a scan tool, ensure that each signal circuit displays LOW when connected to ground.

⇒	If a signal circuit remains HI when connected to ground, replace the IMS harness.

⇒	If a signal circuit other than the circuit being grounded displays LOW, replace the IMS harness.

⇒	If all circuits test normal, replace the IMS.

Component Testing

IMS Direction

IMS Circuits	Park	Reverse	Neutral	Drive 4	Drive 3	Drive 2	Drive 1
Direction Switch Operating Conditions: Ignition ON, range selector in appropriate gear
Transmission Direction Signal R1	HI	LOW	LOW	HI	HI	HI	HI
Transmission Direction Signal R2	LOW	HI	HI	LOW	LOW	LOW	LOW
Transmission Direction Signal D1	HI	HI	LOW	LOW	LOW	LOW	LOW
Transmission Direction Signal D2	LOW	LOW	HI	HI	HI	HI	HI
Transmission Direction Signal Start	LOW	HI	LOW	HI	HI	HI	HI

IMS Range

IMS Circuits	Park	Reverse	Neutral	Drive 4	Drive 3	Drive 2	Drive 1
Range Switch Operating Conditions: Ignition ON, range selector in appropriate gear
Transmission Range Signal A	LOW	LOW	HI	HI	HI	LOW	LOW
Transmission Range Signal B	HI	LOW	LOW	LOW	HI	HI	LOW
Transmission Range Signal C	HI	HI	HI	LOW	LOW	LOW	LOW
Transmission Range Signal P	LOW	HI	LOW	HI	LOW	HI	LOW
Always HI status: Open/short to voltage condition Always LOW status: Short to ground condition

Repair Instructions

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.

•	Manual Shift Shaft Position Switch and Fluid Level Control Valve Removal and Manual Shift Shaft Position Switch and Fluid Level Control Valve Installation for IMS replacement.

•	Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.

•	Automatic Transmission Wiring Harness and Output Speed Sensor Removal and Automatic Transmission Wiring Harness and Output Speed Sensor Installation for automatic transmission control wiring harness extension harness assembly replacement.