2010 Cadillac CTS Sedan AWD V6-3.0L Page 1778
* Replace the control valve body. Refer to Control Valve Lower Body and Upper Body Replacement (See: Transmission and
Drivetrain/Automatic Transmission/Transaxle/Valve Body/Service and Repair).
* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and
Inspection/Programming and Relearning/Service Fast Learn Adapts) following all transmission related repairs.
P1761
DTC P1761
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P1761
- Tap Up Tap Down Shift Switch Signal Message Counter
Circuit/System Description
A 12 volt signal circuit is provided by the body control module (BCM) to the plus or minus buttons. When a plus or minus button is pressed, a
corresponding voltage drop occurs across the resistor network embedded in the switches. This voltage drop is monitored by the BCM. The BCM
will send the request to the transmission control module (TCM) to perform the upshift or downshift. The TCM is constantly monitoring the serial
data sent from the BCM for the correct number and sequence of counts for Tap Up and Tap Down function.
Conditions for Running the DTC
* The TCM rolling counter diagnostic is enabled.
* The Tap Up and Tap Down health message health is received from the BCM.
* The ignition voltage is 8.6 volts or greater.
* The engine speed is 500 RPM or greater for at least 5 seconds.
Conditions for Setting the DTC
The TCM detects an error in the rolling count value that does not match with the BCM count, within 10 seconds.
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 (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)
* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical
Diagrams)
* Body Control System Schematics (See: Body and Frame/Body Control Systems/Diagrams/Electrical Diagrams)
Connector End View Reference
* Component Connector End Views (See: Diagrams/Connector Views)
* Inline Harness Connector End Views (See: Power and Ground Distribution/Multiple Junction Connector/Diagrams)
Description and Operation
* Transmission General Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Transmission General Description)
* Transmission Component and System Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
