Circuit/System Testing: Notes
WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Perform the Transmission Fluid Check
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- Correct the transmission fluid level if the fluid is not at the proper level.
- Using the scan tool, clear the DTC. If DTC P0741 was set, operate the vehicle in D at 72 km/h (45 mph) and use the scan tool to command the TCC ON. Observe the TCC Slip Speed parameter on the scan tool. The TCC Slip Speed should be between -20 to 20 RPM at 20 percent throttle.
- If the TCC Slip Speed is between 150-250 RPM for greater than 5 seconds, inspect the following components and repair or replace as necessary:
- TCC PWM solenoid valve mechanically stuck OFF or leaking.
- TCC regulator apply valve stuck in the OFF position.
- TCC Sol valve stuck in the OFF position or leaking.
- TCC enable valve stuck in the OFF position.
- Misaligned damaged or leaking valve body gasket.
- Inspect the forward clutch input housing assembly for the input shaft fluid seal ring leaking or worn.
- If the TCC Slip Speed is between 150-250 RPM for greater than 5 seconds, inspect the following components and repair or replace as necessary:
- Using the scan tool, clear the DTC. If DTC P0741, P0751 or P0756 is set, drive the vehicle in D and ensure that the TCM commands all gears. The ratios should match the commanded gear for all gears. Refer to Shift Solenoid Valve State and Gear Ratio
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- If the gear ratios do not match the commanded gear, inspect the following and repair or replace as necessary: