Pinpoint Test G : Engagement Quality - Park

• Unable to shift out of park (vehicles equipped with a rotary gearshift knob) 
  • Carry out the line pressure test. If line pressure is low, refer to the Line Pressure Diagnosis Chart for further diagnosis. REFER to: Special Testing Procedures .
  • The shift-by-wire variant of the 10R60 transmission uses hydraulic pressure from the B and D clutches to push the system out of park. Check the B and D clutches for a does not apply condition. REFER to: B Clutch . REFER to: D Clutch .
  • Check the park lock pawl solenoid pin for being stuck extended. REFER to: Transmission .
  • Inspect the park pawl actuator rod, TR sensor and park return spring for damage or binding. Make sure all park components are properly installed and connected. REPAIR or INSTALL new components as necessary. REFER to: Transmission .
  • Remove and inspect the park lock pawl valve. If the valve or bore is damaged, INSTALL a new main control valve body. REFER to: Main Control Valve Body .
  • Disassemble the main control valve body and inspect the park lock pawl valve hydraulic circuits for damage, leaks or blockage. CLEAN or INSTALL new components as necessary. REFER to: Main Control Valve Body .

• Delayed shift out of park when external temperature is less than -20°C (-4°F) (vehicles equipped with rotary gearshift knob) 
  • Extremely cold ambient temperatures can delay the park lock pawl solenoid valve activation up to 10 seconds. To verify, test operation at operating temperatures.

• Unable to engage park (vehicles equipped with a rotary gearshift knob) 
  • Verify park is not manually released. REFER to: Transmission Park by Wire Manual Release .
  • Once out of park, the shift-by-wire variant of the 10R60 transmission uses hydraulic pressure from the A, B, C, D or F clutches to hold the system out of park. If any other observable symptoms indicate one of those clutches is stuck on, RESOLVE that symptom first.
  • Check the park lock pawl solenoid pin for being stuck extended. REFER to: Transmission .
  • Inspect the park pawl actuator rod, TR sensor and park return spring for damage or binding. Make sure all park components are properly installed and connected. REPAIR or INSTALL new components as necessary. REFER to: Transmission .
  • Remove and inspect the park lock pawl valve. If the valve or bore is damaged, INSTALL a new main control valve body. REFER to: Main Control Valve Body .

Possible Sources 

• Park is manually released
• GSM
• Low line pressure
• Clutch fault
• Internal transmission components

Diagnostic steps are not provided for this symptom or DTC. REFER to: Diagnostic Methods