Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 GMC Yukon AT4FACTORY OEM SERVICE PROCEDURE
Power Steering
- Specifications
- Schematic Wiring Diagrams
- Diagnostic Information and Procedures
- DTC C0051
- DTC C1119
- DTC C1146
- DTC C1168
- DTC C116A
- DTC U3000
- DTC U3002
- Symptoms - Power Steering System
- Rattle, Clunk, Pop or Shudder Noise from the Power Steering System
- Whine or Growl Noise from the Power Steering System
- Poor Return of Steering Wheel
- Steering Wheel Surges/Jerks While Turning
- Steering Effort Hard in One or Both Directions
- Repair Instructions
- Steering Gear Boot Replacement (With RC1)
- Steering Gear Boot Replacement (Without RC1)
- Electric Belt Drive Rack and Pinion Steering Gear Replacement (L84, L87 with RC1)
- Electric Belt Drive Rack and Pinion Steering Gear Replacement (L84, L87 without RC1)
- Electric Belt Drive Rack and Pinion Steering Gear Replacement (LM2)
- Power Steering Wiring Harness Extension Harness Replacement (with RC1)
- Power Steering Wiring Harness Extension Harness Replacement (without RC1)
- Power Steering Control Module Wiring Harness Replacement (Power with RC1)
- Power Steering Control Module Wiring Harness Replacement (Power without RC1)
- Power Steering Control Module Wiring Harness Replacement (Torque Sensor with RC1)
- Power Steering Control Module Wiring Harness Replacement (Torque Sensor without RC1)
- Power Steering Assist Motor Replacement
- Power Steering Control Module Calibration
- Description and Operation
- Special Tools and Equipment
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.