General Motors has issued a technical service bulletin (TSB) for certain examples of the 2021 model-year Chevrolet Trailblazer subcompact crossover equipped with the available GM nine-speed automatic transmission for a problem related to the clutch spring retaining ring.
The problem: the clutch spring retaining ring may not be fully seated on certain vehicles equipped with the 9T4X nine-speed automatic transmission. In vehicles with this problem, a warning light indicating a transmission malfunction will appear on the gauge cluster/instrument panel, alerting the driver of the issue. This warning light will appear when the vehicle still shows low mileage on the odometer.
A TSB has also been issued for a similar problem in other GM crossovers equipped with the nine-speed automatic transmission, including the Buick Encore GX, GMC Terrain, Chevy Blazer and Chevy Equinox.
The hazards: GM’s service bulletin for this issue does not indicate what problems the transmission clutch spring retaining ring issue may lead to, although as noted above, the problem will produce a malfunction indicator warning light on the gauge cluster/instrument panel. Additionally, this problem will produce a diagnostic trouble code (or DTC) of P0747.
The fix: Chevy dealers will be instructed to inspect the transmission clutch spring retaining ring in affected vehicles. GM’s TSB indicates this particular service update “involves vehicles in dealer inventory only and will expire on February 22nd, 2022.”
Affected component: transmission clutch spring retaining ring.
- 2021 Chevrolet Trailblazer equipped with 9T4X nine-speed automatic transmission
- General Motors TSB number: A202321841
- Chevy customer service number: 1-800-222-1020