U0101 on Chevrolet
Lost Communication with TCM
U0101 on Chevrolet vehicles indicates lost communication with tcm. Au7o has documented this code across 1 Chevrolet model — most commonly on Silverado 3500HD. This is a network communication code meaning a control module on the vehicle's data bus has lost communication with the Transmission Control Module (TCM). Modern vehicles use a shared data network (commonly CAN bus) so modules can exchange information; when the TCM stops responding or its messages disappear, other modules set this code. Because the transmission relies on this communication to shift properly, the vehicle may go into 'limp' mode, hold one gear, or refuse to shift normally. It generally indicates a wiring, power, ground, or connector problem on the network — or a failed TCM itself — rather than an internal mechanical transmission fault. Typical repair costs on Chevrolet range from $800 to $1,800, depending on the specific model and root cause.
Common Causes of U0101
- •Damaged, corroded, or loose TCM wiring or connectors
- •Open or short in the CAN bus data wiring
- •Blown fuse or lost power/ground to the TCM
- •Corrosion or water intrusion at the TCM connector
- •Faulty Transmission Control Module
- •Another faulty module dragging down the data bus
- •Poor ground connection in the network
U0101 on Chevrolet by Model
Chevrolet Silverado 3500HD(1 issue)
- Allison 1000 Transmission TCM Internal Failure2006-2019
The Transmission Control Module (TCM) mounted internally on the Allison 1000 transmission fails due to heat exposure and vibration. The internal TCM is bathed in transmission fluid and subjected to extreme temperatures. When it fails, the transmission goes into limp mode or refuses to shift from 3rd gear.
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View U0101 across all makes →Frequently Asked Questions
What does U0101 mean on Chevrolet?▼
U0101 stands for "Lost Communication with TCM." This is a network communication code meaning a control module on the vehicle's data bus has lost communication with the Transmission Control Module (TCM). Modern vehicles use a shared data network (commonly CAN bus) so modules can exchange information; when the TCM stops responding or its messages disappear, other modules set this code. Because the transmission relies on this communication to shift properly, the vehicle may go into 'limp' mode, hold one gear, or refuse to shift normally. It generally indicates a wiring, power, ground, or connector problem on the network — or a failed TCM itself — rather than an internal mechanical transmission fault. On Chevrolet specifically, this code is documented across 1 model.
What causes U0101 on Chevrolet vehicles?▼
Common causes on Chevrolet: Damaged, corroded, or loose TCM wiring or connectors, Open or short in the CAN bus data wiring, Blown fuse or lost power/ground to the TCM, Corrosion or water intrusion at the TCM connector, Faulty Transmission Control Module. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U0101 on a Chevrolet?▼
Repair costs on Chevrolet range from $800 to $1,800, depending on the specific model and root cause.
Which Chevrolet models have U0101 documented?▼
Au7o has documented U0101 on 1 Chevrolet model: Silverado 3500HD.