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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 361 (Automatic Transmission - 2ML70 - Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC P0757 >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify that P0721, P0722, P0723, P0966, P0967, P0969, P0970, P0971, P0973, P0974, P0976, P0977, P2720, P2721, P2728, P2729, or P2730 is not set.
  2. Perform the Transmission Fluid Level and Condition Check .
  3. Perform the Line Pressure Check .
  4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
  5. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .
    • If the shift solenoid 2 is found to be leaking or stuck ON, replace the Q8 control solenoid valve assembly.
    • If the Q8 control solenoid valve assembly tests normal, inspect the valve body and hydraulic circuits for a leak or a stuck valve.
  6. Listed in the chart below are conditions for each component that could set DTC P0757. Carefully inspect each component for that condition. Repair or replace as necessary.
DTC Component Condition
P0757 Control Valve Body Upper Assembly (343) Shift Solenoid Valve Mode B (332) stuck - debris, sediment, binding or scored bore
P0757 Control Valve Channel Plate (304) Control Valve Channel Plate damaged or contaminated with large debris
P0757 Control Solenoid (w/Body and TCM) Valve Assembly (307) Shift Solenoid (SS) 2:
  • O-ring seals leaking
  • Control signal fluid supply leak - valve body filter plate assembly cracked or damaged gasket seal (307)
P0757 Control Solenoid Valve Assembly (307) Pressure Switch 1:
  • O-ring seals leaking
  • Torn or cracked diaphragm
P0757 4th clutch slipping or damaged