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.
SYS.OK|MANUAL.DBβ LIVE
HOMESERVICE MANUALSCHEVROLET2009AVALANCHE 6.0 Y, RWDREPAIR AND DIAGNOSISTRANSMISSIONAUTOMATIC TRANSAUTOMATIC TRANSMISSION - 6L80/6L90 - DTC P0218 TO DTC P0963DTC P0218CIRCUIT/SYSTEM TESTING
2009 Chevrolet Avalanche 6.0 Y, RWD
Circuit/System Testing
2009 Chevrolet Avalanche 6.0 Y, RWDSECTION Circuit/System Testing
- Inspect the transmission cooling system for restrictions or damage, inducing any auxiliary cooler if equipped.
- Perform the Transmission Fluid Cooler Flushing and Flow Test
to verify proper transmission oil cooler flow.
- If a concern is found, repair or replace the damaged components as necessary.
- Perform the Line Pressure Check
to verify proper transmission line pressure.
- If a concern is found repair or replace the damaged components as necessary.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.