P0751 on GMC: How to Diagnose & Fix
Shift Solenoid A Performance/Stuck Off
4 GMC models · 4 documented issues · 3 critical · $150-$4,500 repair
P0751 on GMC by model: symptoms, diagnosis and fix
The 2010-2017 Terrain uses the GM 6T40 (2.4L) and 6T45 (V6) 6-speed automatic transmissions, both of which suffer from torque converter shudder, harsh shifts, and solenoid failures. The shudder occurs at light throttle between 30-50 mph when the torque converter clutch locks up. Solenoid pack wear causes P0756, P0751, and P0776 transmission fault codes. The transmission is sensitive to fluid condition — the 6T40/6T45 was originally filled with Dexron VI, but older Dexron VI degrades faster than newer formulations.
Common Symptoms
- Shudder at light throttle 30-50 mph
- Harsh 1-2 or 2-3 upshift
- Hesitation or lurch when pulling away from a stop
- Transmission fault codes P0756, P0751, P0776
- Check engine light
- Delayed engagement from Park to Drive when hot
How to Fix
Full fluid exchange with Dexron VI (ACDelco 10-9243 or equivalent). TCM calibration update. Solenoid pack replacement (GM 24272814) if codes present. Valve body replacement for internal failures. Fluid service every 40,000 miles recommended for stop-and-go use.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Dexron VI full-synthetic automatic transmission fluidOEMACDelco 10-9243 (GM 88865549)Cross-refValvoline DEXRON VI ATF 822405, Mobil 1 Synthetic ATF Dexron VI 112980, Castrol Transmax DEXRON-VI 03520C$8–$15
Dexron VI is required — do NOT substitute Dexron III or a universal/multi-vehicle ATF, as the friction
- Control solenoid valve assembly (valve body + solenoids + TEHCM) — 2.4L, 2012-2013OEM24041960$600–$960
THIS is the part that actually fixes P0751/P0756/P0776 on the 6T40/6T45. GM does not sell the individual shift/pressure-control solenoids for this transmission as a serviceable part — the solenoids are integrated into the TEHCM/valve bod…
- Control solenoid valve assembly (valve body + solenoids + TEHCM) — 2.4L, 2014-2017OEM24041961$598–$915
Same function as 24041960 but the correct number for the later 2.4L Terrain — this is the year split, so do not cross-order between them.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
The Allison 1000 (gas) and Allison 2000 (diesel) 6-speed automatic transmissions used in Sierra 2500HD/3500HD are widely regarded as extremely durable, but the Transmission Control Module (TCM) and solenoid pack do develop faults. Common issues include harsh 1-2 shifts, transmission sticking in one gear, slip codes, and the truck going into limp mode (3rd gear only). The Allison's proprietary Transynd fluid is critical — using non-approved fluid is the leading cause of premature solenoid wear. TCM software updates from GM address most calibration-related shift complaints.
Common Symptoms
- Harsh or clunky 1-2 upshift
- Transmission stuck in 3rd gear (limp mode)
- Delayed engagement from Park to Drive
- Slip or flare during 2-3 shift
- Check engine light with transmission codes (P0700, P0730, P0751)
- Transmission not shifting above 3rd gear under load
How to Fix
TCM software update at dealer. Allison Transynd fluid service (drain/fill every 30k miles, full exchange every 60k). Solenoid pack replacement (Allison 29539579). TCM replacement if software update fails. Always use genuine Allison Transynd TES-295 or Mobil Delvac 1 ATF — not GM DEXRON products.
Sources for this issue (1)
Same 4L60E transmission issues as Chevrolet C/K. Sun shell failure, 3-4 clutch pack burnup, and worn input drum.
Common Symptoms
- Slipping in 3rd or 4th gear
- Harsh shifts
- No 3rd gear
- Burnt fluid
How to Fix
Sources for this issue (1)
On GMT800 Sierra 1500 trucks equipped with the 4L60-E family automatic, a well-known internal failure is cracking or stripping of the reaction sun shell. Owners commonly report sudden loss of reverse, no 2nd gear, no 4th gear, or a truck that starts in 3rd gear after a bang or flare. This is widely documented in transmission rebuild literature, repair databases, and owner reports for GM trucks and SUVs using this transmission.
Common Symptoms
- loss of reverse
- no 2nd gear
- no 4th gear
- harsh bang followed by missing gears
- transmission starts in 3rd gear
- slipping on acceleration
How to Fix
Diagnosis usually starts with verifying gear loss patterns, checking line pressure, and scanning for ratio/performance codes before condemning the unit. Repair requires transmission removal and overhaul or replacement, typically installing an upgraded hardened sun shell such as the commonly recommended 'Beast' style shell along with inspection of clutches, band, pump, and valve body wear items.
Sources for this issue (1)
P0751 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 P0751 mean on a GMC?
P0751 stands for "Shift Solenoid A Performance/Stuck Off." This code means the transmission control module commanded Shift Solenoid A (sometimes called Shift Solenoid 1) but the transmission did not respond properly, with the solenoid acting as though it is stuck 'off.' Shift solenoids are electrically operated valves that direct hydraulic fluid pressure to engage gears, so when one underperforms the transmission may shift harshly, slip, or fail to change gears at the right time. The computer sets this code when the measured gear ratio or shift behavior does not match the commanded state. It generally indicates a hydraulic or performance issue with the solenoid or the fluid circuit it controls inside the automatic transmission. On GMC it is documented across 4 models: Terrain, Sierra 2500HD, C/K 1500, Sierra 1500.
What are the most common causes of P0751?
The most common causes of P0751 are: Stuck or failed Shift Solenoid A, Low, dirty, or degraded transmission fluid, Clogged solenoid screen or valve body passages, Sticking or worn valve body components, Wiring or connector problem at the solenoid, Internal transmission mechanical wear, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P0751 on a GMC?
Published repair estimates on GMC range from $150 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 P0751 on a different make?
View P0751 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.