Chevrolet Trax: DTC P1761
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 Descriptor
DTC P1761
Up and Down Shift Switch Signal Message Counter Incorrect
Circuit/System Description
When the shift lever is placed in the M position, the transmission will enter
manual mode, also known as tap
shift. The manual mode allows the vehicle operator to select an upshift by
pressing the plus (+) button or
downshift by pressing the minus (-) button. The body control module (BCM)
supplies a signal circuit to the
shift controller. The shift controller has switches connected to a resistor
array. A voltage drop occurs across the
resistor network. When the plus or minus button is pushed, a corresponding
voltage drop occurs across the
resistor network. This voltage drop is monitored by the BCM. The BCM will send
the request to the
transmission control module (TCM) for an upshift or downshift. The BCM internal
counter increments each
time the tap shift signal status is sent and the BCM sends the rolling count
with the tap shift signal status. The
TCM counter increments each time the tap shift signal status is received. The
DTC will set if the rolling count
value of the TCM does not match the rolling count sent from the BCM.
Conditions for Running the DTC
- Engine speed is 400-7,500 RPM for 5 s.
- Runs continuously when above condition is met.
Conditions for Setting the DTC
TCM detects the internal rolling count value does not match the expected BCM
count, 3 times within 10 s.
Action Taken When the DTC Sets
- P1761 is a Type C DTC.
- TCM inhibits the Tap Up Tap Down function.
- TCM inhibits manual shifting of forward gears.
Conditions for Clearing the DTC
P1761 is a Type C DTC.
Reference Information
Schematic Reference
- Automatic Transmission Controls Schematics (Encore, MH8 or MHB) ,
Automatic Transmission
Controls Schematics (Trax, MH8 or MHB)
- Body Control System Schematics (Encore) , Body Control System
Schematics (Trax)
- Data Communication Schematics (Encore) , Data Communication
Schematics (Trax)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - TRAX
- Inline Harness Connector End Views (Encore) , Inline Harness
Connector End Views (Trax)
Description and Operation
- Electronic Component Description
- Transmission Component and System Description
- Transmission General Description
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 (LUV) ,
Powertrain Diagnostic Trouble
Code (DTC) Type Definitions (2H0)
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE:
- DTC P1761 is an informational DTC.
- Diagnose all other body control module DTCs prior to DTC P1761.
- Verify there are no other body control module or communication DTCs set.
If a DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
If a DTC is not set
- Complete the diagnosis by looking for a GMLAN circuit fault. Refer to
Scan Tool Does Not
Communicate with High Speed GMLAN Device .
If a GMLAN circuit fault is found
Repair as necessary.
If a GMLAN circuit fault is not found
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Perform the Transmission Adaptive Values Learn following all
transmission repairs
- Control Module References - for Body Control Module and Control Solenoid
Valve Assembly
replacement, programming and setup
READ NEXT:
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.
Diag
Up and Down Shift Enable Switch Circuit Low Voltage
Circuit/System Description
When the shift lever is placed in manual mode (M), the driver shift request ,
also known as the tap shift
function, is a
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.
Diag
SEE MORE:
If available, the controls are on the
climate control panel. To operate,
the engine must be running.
Press or
to heat the driver or
passenger seat.
See Heated Front Seats
Head Restraint Adjustment
Do not drive until the head restraints
for all occupants are installed and
adjusted properly.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
5
Obtaining rotational speed for the components rotating at tire/wheel speed is
critical to systematically
eliminating specific vehicle component groups. These component rotational speeds
can be generated by
usin