2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1633
* The TCM commands maximum line pressure.
* The TCM inhibits Tap Up/Down function.
* The TCM inhibits manual shifting of forward gears.
* The TCM freezes transmission adaptive functions.
* The TCM limits the transmission to 3rd and reverse operation.
Conditions for Clearing the DIC/DTC
DTCs P0776 and P0777 are Type A DTCs.
Diagnostic Aids
Before performing a road test, configure and setup the scan tool for snapshot mode. This will allow you to display, monitor, and verify multiple
transmission data parameters at one time, after the road test.
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/Connector End Views By Name)
* Inline Harness Connector End Views (See: Diagrams/Connector Views/Multiple Junction Connector/Connector End Views By Number)
Description and Operation
Transmission General Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and Operation/6T70/6T75 -
Automatic Transmission/Transmission General Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)
Circuit/System Verification
1. Engine idling in Park, with parking brake applied and drive wheels chocked.
2. Perform the Transmission Fluid Level and Condition Check (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing
and Inspection/Component Tests and General Diagnostics/6T70/6T75 - Automatic Transmission/Transmission Fluid Level and Condition
Check) to verify correct fluid level and condition.
3. Monitor the Transmission Fluid Pressure (TFP) Switch 1 with a scan tool. Place the gear select lever in Park, Reverse, and Neutral range.
Verify the TFP Switch 1 parameter states are correct for Park, Reverse, and Neutral. Refer to Transmission Fluid Pressure Switch Logic (
See: Specifications/Mechanical Specifications/Automatic Transmission/Transaxle/System Specifications/6T70/6T75 - Automatic
Transmission/Transmission Fluid Pressure Switch Logic).
4. Place the gear select lever in Drive range. Command the shift transmission with a scan tool through all forward ranges. Verify the TFP
Switch 1 parameter states are correct for all forward ranges. Refer to Transmission Fluid Pressure Switch Logic (See:
Specifications/Mechanical Specifications/Automatic Transmission/Transaxle/System Specifications/6T70/6T75 - Automatic
Transmission/Transmission Fluid Pressure Switch Logic).
5. Engine idling in Park, verify with a scan tool the Transmission ISS/OSS Supply Voltage parameter displays OK.
6. Engine idling in Park. Observe the Transmission ISS parameter on the scan tool, while varying the engine speed. The Transmission ISS
parameter should vary with engine speed and not drop out.
7. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the Transmission OSS parameter on the scan tool. The Transmission OSS
parameter should vary with the vehicle speed and not drop out.
Note: Perform a scan tool snapshot, during the road test.
8. Perform the Road Test (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and Inspection/Initial Inspection and
