P1761

DTC P1761

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 P1761
- Up and Down Shift Switch Signal Circuit

Circuit/System Description

The driver shift request (DSR), also known as the TAP Up/Downshift manual shift function, allows the driver to select the desired range of gears for current driving conditions. The DSR shift system is activated when the gear selector is in the manual position. The DSR system is deactivated in all other range positions. When DSR is selected, a signal is sent to the body control module (BCM) and the also to the transmission control module (TCM). Each time a signal is sent, an internal counter in the BCM and TCM increments. Both counters must have the same value. This code sets when the rolling count value of the TCM does not match the same rolling count value sent from the BCM.

Conditions for Running the DTC

The engine speed is 400 RPM or greater for 5 seconds.

Conditions for Setting the DTC

The TCM detects an error in the rolling count value that does not match with the BCM.

Action Taken When the DTC Sets

* DTC P1761 is a Type C DTC.
* The TCM disables TAP Shift operation.

Conditions for Clearing the DTC

DTC P1761 is a Type C DTC.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics 6L45/6L50/6L80/6L90 - Automatic Transmission
Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
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

Description and Operation

Electronic Component Description Electronic Component Description
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

Circuit/System Verification

Note: If other DTCs are set, diagnose those DTCs first.

If no other DTCs are set, diagnosis is accomplished by testing for a condition on the CAN circuit. Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with High Speed GMLAN Device.

Repair Instructions

* Perform the Reset Transmission Adapts Reset Procedure following all transmission related repairs.
* Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Refer to Control Module References Control Module References for Control Solenoid Valve Assembly replacement, programming, and setup.