The drivers shift request (DSR), also known as the TAP Shift, allows the driver to select the desired range of gears for current driving conditions. Pressing the plus (+) switch will increase the highest attainable gear and pressing the minus (-) switch will decrease the highest attainable gear. The TCM will not allow a downshift if the transmission is compromised by overspeeding. The DSR shift switch is a resistor array and is located on the automatic transmission gear shift lever. The BCM supplies a 12 volt reference circuit and signal circuit to the DSR. The DSR shift system is activated when the gear selector is in the Manual (M) position. The DSR system is deactivated in all other range positions.

The tow/haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul mode switch is pressed and released, the tow/haul switch signal circuit to the BCM is momentarily toggled to zero volts. The BCM communicates the tow haul switch input to the TCM via GMLAN. When tow/haul mode is active, the transmission control module (TCM) changes the shift pattern to generally raise the output speed that an upshift or downshift is made and also applies the TCC in second range. When the tow/haul mode switch is pressed and released again, the BCM communicates the request to the TCM and tow/haul mode becomes inactive. The transmission upshift and downshift speeds and TCC command return to a normal shift pattern.

P1761

This DTC sets if the DSR information is not received or the expected value is not met within a 10 second period.

P1762

This DTC sets if the Tow/Haul Mode information is not received or the expected value is not met within a 10 second period.

P1761

P1762

DTCs P1761 and P1762 are Type C DTCs.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

P1761

1. Ignition ON, verify with a scan tool the Tap Up/Down Switch parameter displays On.
2. Ignition ON, cycle the automatic transmission manual shift switch up and down, while observing the Tap Up/Down parameter.

⇒	The parameter should change to Up when the plus (+) switch is selected, and to Down when the minus (-) switch is selected.

3. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

P1762

1. Ignition ON, cycle the tow/haul switch while observing the Tow/Haul Mode parameter on the scan tool. The Tow / Haul Mode parameter should change states between Active and Inactive with each cycle of the switch.
2. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

If other DTCs are set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.