2010 Cadillac CTS Sedan AWD V6-3.0L Page 1780
Circuit/System Description
The drivers shift control (DSC) also known as the Tap UP/Down feature allows the driver to shift or change gears similar to a manual transmission.
Activating the DSC is accomplished by placing the shift lever in the manual (M) mode position. To place the shift lever in M position, move the
shift lever to the right from the drive (D) position gate. When the shift lever is in the M position an upshift is accomplished pushing the shift lever
forward. A downshift is accomplished by pulling back or pushing rearward on the shift lever. A redundant set of Tap UP/Down switches are
available on the steering wheel horizontal crossbar facing the instrument panel. The plus (+) switch is located on the right side of the steering wheel
and the minus (-) switch is located on the left side of the steering wheel. A 12 volt parallel circuit from the body control module (BCM) supplies
voltage to the automatic transmission manual shift switch on the shift lever and to the automatic transmission manual shift switches on the steering
wheel. A separate signal circuit from each switch to the BCM provides the information on each Tap Up/Down command. The BCM sends the
requested command on the serial data line to the transmission control module (TCM) to perform the shift.
Conditions for Running the DTC
P1765, P1766, or P1767
* DTCs P1761, P1765, P1766, P1767, P182E, and P1915 are not set.
* Ignition voltage is greater than 8.6 volts.
* The engine speed is greater than 500 RPM for 5 seconds.
Conditions for Setting the DTC
P1765
The TCM detects a Stuck ON tap up switch for 1 second in PARK, NEUTRAL, and in manual position for 600 seconds, when the tap down switch
is depressed.
P1766
The TCM detects a Stuck ON tap down switch for 1 second in PARK, NEUTRAL, and in manual position for 600 seconds when the tap up switch
is depressed.
P1767
The TCM detects an invalid voltage on the TAP Up/Down Signal Circuit for 1 minute.
Action Taken When the DTC Sets
* DTCs P1765, P1766, and P1767 are Type C DTCs.
* The TCM disables TAP shift functions.
Conditions for Clearing the DTC
DTCs P1765, P1766, and P1767 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/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)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
