P0894 on Buick: How to Diagnose & Fix
Transmission Component Slipping
1 Buick model · 1 documented issue · 1 critical · $900-$4,500 repair
P0894 on Buick by model: symptoms, diagnosis and fix
The nine-speed automatic in later Envisions produces a violent intermittent clunk when engaging or shifting in Drive - described by one owner as 'so violent, it shakes the entire car' - with a tendency to slip on the 1-2 and 2-3 shifts, appearing around 14,000-15,000 miles. On Gen2 cars the same family of complaints escalates to a 'Service Transmission Soon' message with a total loss of acceleration that feels like the car dropped into neutral. One documented repair required replacing BOTH valve bodies, where the dealer found a nicked O-ring seal during disassembly. GM TSB 21-NA-169 provides diagnostic procedures for 9T45/9T50/9T60 fault codes, and TSB 23-NA-153 documents which shift delays are considered normal.
Common Symptoms
- Loud violent clunk when shifting or engaging Drive
- Slipping between 1st-2nd and 2nd-3rd gears
- 'Service Transmission Soon' message
- Loss of acceleration as if the car shifted into neutral
- Jerking at 20-40 mph
How to Fix
Scan the TCM and follow GM TSB 21-NA-169 for 9T45/50/60 diagnostics rather than accepting a 'drive it until it fails' answer. Confirm fluid level and condition with the correct DEXRON HP fluid at the specified temperature, check for updated TCM calibrations, and inspect the valve body and its O-ring seals - replacement of the valve body assembly is the documented fix. After the repair the adaptive shift learning needs time to relearn, so some initial jerkiness is expected.
Sources for this issue (3)
- 2019 Buick Envision - Loud Clunk When Shifting (NHTSA/owner complaints at ~14,500 miles)article
- 2021 Buick Envision - Loss Of Power When Driving And Message Of No Acceleration (both valve bodies replaced, nicked O-ring found)article
- 2021 Buick Envision TSBs - 21-NA-169 diagnostic procedures for 9T45/50/60 transmissions with fault codestsb
P0894 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0894 mean on a Buick?
P0894 stands for "Transmission Component Slipping." This generic transmission code means the PCM/TCM detected that a rotating component inside the transmission is slipping, by comparing input and output speeds and finding more difference than there should be for the commanded gear. Slippage indicates clutches or bands are not holding properly, which can quickly worsen and damage the transmission through overheating and accelerated wear. It often comes with rough or flaring shifts, reduced power, and overheating, and should be addressed promptly. On Buick it is documented across 1 model: Envision.
What are the most common causes of P0894?
The most common causes of P0894 are: Low, dirty, or burnt transmission fluid, Worn clutch packs or bands, Faulty shift or pressure control solenoid, Internal hydraulic/valve body problems, Worn torque converter, Faulty speed sensors giving false slip readings, General internal transmission wear. The specific cause varies by vehicle.
How much does it cost to fix P0894 on a Buick?
Published repair estimates on Buick range from $900 to $4,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0894 on a different make?
View P0894 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.