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.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2010AVALANCHE 1500 2WD V8-5.3LREPAIR AND DIAGNOSISTRANSMISSION AND DRIVETRAINAUTOMATIC TRANSMISSION/TRANSAXLEDESCRIPTION AND OPERATION2ML70 - AUTOMATIC TRANSMISSIONPOWER OFF HIGH DEFAULT
2010 Chevrolet Avalanche 1500 2WD V8-5.3L
Power Off High Default
2010 Chevrolet Avalanche 1500 2WD V8-5.3LSECTION Power Off High Default
Power Off High Default
If the transmission is in Third or Fourth gear during a transmission electrical component malfunction, the transmission will defualt to high. All solenoids will default to their normal state. The transmission will remain in Power Off High Default until the ignition has been turned off, or the transmission is shifted to Reverse (R). When the vehicle is restarted, and shifted back into Drive (D), the transmission will then operate in Power Off Low Default. This default action enables the vehicle to be safely driven to a service center.
Hybrid Direct, 2-3-4 Clutch Remains Applied
Pressure Control (PC) Solenoid 3 Trim
The PC solenoid 3 trim defaults to its normally high state (ON) allowing actuator feed limit fluid to enter the PCS 3 signal circuit. PCS 3 signal fluid is then routed through orifice #34 to the hybrid low, 1-2 clutch regulator valve; through orifice #33 to the hybrid low, 1-2 clutch boost valve; and to the shift solenoid valve - mode B.
Shift Solenoid 2
The shift solenoid 2 defaults to its normally closed state (OFF), allowing solenoid 2 signal fluid to exhaust from the shift solenoid valve - mode B.
Shift Solenoid Valve - Mode B
PCS 3 signal fluid pressure acts on a differential area of the shift solenoid valve - mode B, holding the valve in the applied position against shift solenoid valve - mode B spring force. This allows HD 234 clutch/B cooling feed fluid pressure to continue to feed the HD 234 clutch circuit.
Hybrid Direct, 2-3-4 Clutch Assembly
HD 234 clutch fluid is directed to the hybrid direct, 2-3-4 clutch piston to apply the hybrid direct, 2-3-4 clutch plates.
1-3 Clutch Releases
If the transmission is operating in Third gear when an electrical malfunction occurs, the normally closed shift solenoid 1 and the normally low pressure control solenoid 4 trim default to their normal states (OFF) and the 1-3 clutch is released. Refer to Drive Range - Fourth Gear (Fourth Gear) for a complete discription of 1-3 clutch release.
4th Clutch Releases
If the tranmission is operating in Fourth gear when an electrical malfunction occurs, the shift solenoid 1 defaults to its normally closed state (OFF) and the 4th clutch is released. Refer to EVT Mode High - From Drive Range 4th Gear (EVT Mode High - From Drive Range 4th Gear) for a complete description of 4th clutch release.
Power Off High Default
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra 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.