LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2021 >> XT5 Sport >> Repair and Diagnosis >> External Pages >> Different car >> Section 838 (Automatic Transmission - 10L1000 (MGM MGU) - Diagnostic Information And Procedures (1 Of 2)) >> Diagnostic Information and Procedures >> DTC P0776 or P0777 >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify the condition does not exist: Incorrect fluid level or condition - Refer to: Transmission Fluid Level and Condition Check
    • If a condition exists 

      Repair or replace as necessary

    • Go to next step: If no condition exists 
  2. Ignition - On/Vehicle - In Service Mode
  3. NOTE:
    • For this test, the following scan tool parameter temperature needs to be between 20 and 80°C (68 and 176°F): Transmission Fluid Temperature
    • The scan tool control function may turn off after 30 s.
  4. Perform the scan tool function: Transmission Control Solenoid Valve 2 - Enabled - For greater than 2 s

    Verify the difference between the following parameters is less than 0.05 A:

    • Transmission Control Solenoid Valve 2 Current
    • Transmission Control Solenoid Valve 2 Current Command
    • If the difference is 0.25 A or greater 

      Repair or replace the following as necessary:

    • If the difference is between 0.05 and 0.25 A 

      Perform the following steps:

      NOTE:
      • Determining the difference between the current parameters of the components will determine if a high resistance condition is present.
      • This step compares the original component that set the DTC with a known good component (referred to as X) on this vehicle (same type) that does not have a DTC set.
    1. Perform the scan tool function: Transmission Control Solenoid Valve 2 - Enabled - For greater than 2 s

      Monitor and record the difference between the following scan tool parameters:

      • Transmission Control Solenoid Valve 2 Current Command
      • Transmission Control Solenoid Valve 2 Current
    2. Perform the scan tool function: Transmission Control Solenoid Valve X - Enabled - For greater than 2 s@A known good component on this vehicle (same type) - Refer to: Transmission Solenoid Information

      Monitor and record the difference between the following scan tool parameters:

      • Transmission Control Solenoid Valve X Current Command
      • Transmission Control Solenoid Valve X Current
    3. Verify the difference between the two recorded values is 0.05 A or less - The original component that set the DTC & A known good component on this vehicle (same type)
      • If the difference between the recorded values is greater than 0.05 A - Repair or replace the following as necessary:
      • Go to next step: If the difference between the recorded values is 0.05 A or less
    4. Refer to step 4
    • Go to next step: If the difference is less than 0.05 A 
  5. Clear DTCs
  6. Road test the vehicle. - Refer to: Road Test
  7. Verify DTC P0716, P0717, P0721, P0722, P0723, P077C, P077D, P07BF, P07C0, P172A, P172B, P176B, P176C, P176D, P1783, P178F, P17C5, P17C6, P17CC, P17CD, P17CE, P17D3, P17D6 is not set.
    • Go to next step: If none of the DTCs are set 
  8. Verify that no DTC listed in the DTC Descriptor Category is set.
    • If any DTC listed in the DTC Descriptor Category is set 

      Refer to: Diagnostic Fault Information

    • Go to next step: If none of the DTCs listed in the DTC Descriptor Category is set 
  9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

    Verify that no DTC listed in the DTC Descriptor Category is set.

    • If any DTC listed in the DTC Descriptor Category is set 

      Refer to: Diagnostic Fault Information

    • Go to next step: If none of the DTCs listed in the DTC Descriptor Category is set 
  10. All OK.