Operation CHARM: Car repair manuals for everyone.
Home >> Chevy Truck >> 2012 >> Tahoe 4WD V8-6.0L Hybrid >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P183B

P183B




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

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 P181C
- Internal Mode Switch 2 R1 Circuit Low Voltage

DTC P181D
- Internal Mode Switch 2 R1 Circuit High Voltage

DTC P181E
- Internal Mode Switch 2 R2 Circuit Low Voltage

DTC P181F
- Internal Mode Switch 2 R2 Circuit High Voltage

DTC P183A
- Internal Mode Switch 2 D1 Circuit Low Voltage

DTC P183B
- Internal Mode Switch 2 D1 Circuit High Voltage

DTC P183C
- Internal Mode Switch 2 D2 Circuit Low Voltage

DTC P183D
- Internal Mode Switch 2 D2 Circuit High Voltage

DTC P183E
- Internal Mode Switch 2 - Invalid Range

DTC P184A
- Internal Mode Switch 2 S Circuit Low Voltage

DTC P184B
- Internal Mode Switch 2 S Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

The internal mode switch assembly is a sliding contact switch attached to the control valve body within the transmission. The internal mode switch is integrated into the Manual Shift Shaft Position Switch and is not serviced separately. The nine 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 module is high when the switch is open and low when the switch is closed to ground.

Conditions for Running the DTC

* The ignition is ON.
* Ignition voltage is greater than 6.0 V.

Conditions for Setting the DTC

The internal mode switch state does not match the selected gear for 3 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Diagnostic Aids

* The internal mode switch assembly can be damaged by electric current exceeding 25 mA. Test the internal mode switch assembly for an open condition whenever a short to voltage condition is observed.
* The internal mode switch is a non-serviceable part of the manual shift shaft position switch.
* The internal mode switch parameter displaying HI for each range indicates an open ground circuit or connector for the internal mode switch.

Reference Information
Schematic Reference

Hybrid Controls Schematics Hybrid Controls Schematics
Connector End View Reference

Component Connector End Views Connector Views
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 Control Module References for scan tool information
Special Tools

* DT-47825-10 - Jumper Harness
* DT-48493 - Jumper Harness

For equivalent regional tools, refer to Special Tools Tools and Equipment.

Circuit/System Verification

Ignition ON, observe the scan tool internal mode switch 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 table below:






Circuit/System Testing

1. Ignition OFF. Disconnect the X176 24-way harness connector at the transmission. Additional DTCs may set.
2. Install the DT-48493 - jumper harness to the harness side only.
3. Ignition 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 ohm between the low reference circuit terminal 5 and ground.

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

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

• If any parameter displays low, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the T6 drive motor generator power inverter module.

* Parameter D1 - terminal 3
* Parameter D2 - terminal 4
* Parameter R1 - terminal 1
* Parameter R2 - terminal 2

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

• If a parameter displays high when grounded, test the signal circuit terminal listed below for a short to voltage or an open/high resistance. If the circuit tests normal, replace the T6 drive motor generator power inverter module.

* Parameter D1 - terminal 3
* Parameter D2 - terminal 4
* Parameter R1 - terminal 1
* Parameter R2 - terminal 2

6. Ignition OFF, disconnect the X1 16-way harness connector at the transmission.
7. Install the DT-47825-10 - jumper harness to the harness side only.
8. Ignition ON, verify the scan tool S parameter displays high.

• If the S parameter displays low, test the signal circuit terminal 3 X1 for a short to ground. If the circuit tests normal, replace the T6 drive motor generator power inverter module.

9. Install a 3 A fused jumper wire between the signal terminal 3 X1 and ground. Verify the scan tool S parameter is low.

• If the S parameter displays high, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the T6 drive motor generator power inverter module.

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

Component Testing

1. Ignition OFF. Disconnect the X176 24-way harness connector at the transmission.
2. Install the DT-48493 - jumper harness to the transmission side only.
3. Disconnect the X1 16-way harness connector at the transmission.
4. Install the DT-47825-10 - jumper harness to the transmission side only.
5. Transmission in PARK, test for less than 10 ohm between the low reference circuit terminal 5 at the transmission and each signal circuit terminal listed below at the transmission:

* Terminal D2 X176
* Terminal R2 X176
* Terminal S X16

• If not within the specified range, test the transmission internal extension harness signal circuit for an open/high resistance, if the circuit tests normal replace the automatic transmission internal B15 mode switch.

6. Test for infinite resistance between the low reference circuit terminal 5 at the transmission and each signal circuit terminal listed below at the transmission:

* Terminal D1 X176
* Terminal R1 X176

• If not the specified value, test the transmission internal extension harness signal circuit for a short to ground, if the circuit tests normal replace the automatic transmission B15 internal mode switch.

7. Parking brake applied with the transmission in NEUTRAL, test for less than 10 ohm between the low reference circuit terminal 5 at the transmission and each signal circuit terminal listed below at the transmission:

* Terminal D1 X176
* Terminal R1 X176

• If not within the specified range, test the transmission internal extension harness signal circuit for an open/high resistance, if the circuit tests normal replace the automatic transmission B15 internal mode switch.

8. Test for infinite resistance between the low reference circuit terminal 5 at the transmission and each signal circuit terminals listed below at the transmission:

* Terminal D2 X176
* Terminal R2 X176

• If not the specified value, test the transmission internal extension harness signal circuit for a short to ground, if the circuit tests normal replace the automatic transmission B15 internal mode switch.

9. Transmission in REVERSE, test for infinite resistance between the low reference circuit terminal 5 at the transmission and the signal circuit terminal 3 X1 at the transmission.

• If not the specified value, test the transmission internal extension harness signal circuit for an open/high resistance, if the circuit tests normal replace the automatic transmission B15 internal mode switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Manual Shift Shaft Position Switch Replacement 2ML70 - Automatic Transmission
* Transmission Control Wiring Harness Extension Harness Removal 5. Transmission Control Wiring Harness Extension Harness Removal
* Control Module References Control Module References for Drive Motor Generator Power Inverter Module replacement, setup and programming

pro multis · About Operation CHARM