What are the most common GMC Sierra 2500HD problems?

According to Au7o's analysis of 510+ owner reports, the 2025 GMC Sierra 2500HD has 1 documented issue. The documented issue is: Allison 1000/2000 Transmission TCM Failure and Harsh Shifting. Of these, 1 is rated critical and should be addressed promptly.

Is the GMC Sierra 2500HD reliable?

The 2025 GMC Sierra 2500HD has 1 known issue documented across 510+ owner reports. 1 issue is rated critical: Allison 1000/2000 Transmission TCM Failure and Harsh Shifting. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common GMC Sierra 2500HD problems?

Repair costs for known GMC Sierra 2500HD issues range from $300 to $4,500, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Allison 1000/2000 Transmission TCM Failure and Harsh Shifting, typically costs $300-$4,500 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2011-2025 GMC Sierra 2500HD Allison 1000/2000 Transmission TCM Failure and Harsh Shifting?

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, transmiss… Repairs typically run $300-$4,500. Severity: high.

GMC · Known Issues

2025 GMC Sierra 2500HD Problems: 1 Issue Every Owner Should Know

2025 model year · 510+ owner reports · Updated June 2026

Share:@au7o.io

According to Au7o's analysis of 510+ owner reports, the 2025 GMC Sierra 2500HD has 1 documented issue, with 1 rated critical. The most serious is Allison 1000/2000 Transmission TCM Failure and Harsh Shifting ($300-$4,500 repair). The most commonly reported issue is Allison 1000/2000 Transmission TCM Failure and Harsh Shifting with 510 owner reports. Across all issues with published estimates, repair costs range from $300 to $4,500. DIY maintenance guides at au7o.io.

2025 GMC Sierra 2500HD Problems: 1 Issue Every Owner Should Know

All 1 Known Issue

2011-2025 GMC Sierra 2500HD: Allison 1000/2000 Transmission TCM Failure and Harsh Shifting#

Common Symptoms

How to Fix

Owner tips & cautions

Research This Issue

Other GMC Models

Frequently Asked Questions

What are the most common GMC Sierra 2500HD problems?

Is the GMC Sierra 2500HD reliable?

How much does it cost to fix common GMC Sierra 2500HD problems?

What is the 2011-2025 GMC Sierra 2500HD Allison 1000/2000 Transmission TCM Failure and Harsh Shifting?