GMC Sierra 3500HD Problems: 16 Issues Every Owner Should Know

2007-2024 model years · 1,600+ owner reports · Updated April 2026

According to Au7o's analysis of 1,600+ owner reports, the 2007-2024 GMC Sierra 3500HD has 16 documented known issues, with 7 rated critical. The most serious are CP4.2 High-Pressure Fuel Pump Catastrophic Failure ($10,000-$18,000 repair), Trailer brake controller / integrated trailer brake module malfunction ($80-$900 repair), Transfer case pump rub causing fluid leak and transfer case damage (4WD) ($450-$2,800 repair), Electric power steering (EPS) assist loss / reduced assist warnings (new body style), Allison 1000 Transmission Control Module and Sensor Failures ($500-$3,500 repair), Diesel Injector Failure Causing White Smoke and Rough Running ($600-$5,000 repair) and Rear Leaf Spring Breakage Under Heavy Loads ($400-$1,500 repair). The most commonly reported issue is CP4.2 High-Pressure Fuel Pump Catastrophic Failure with 440 owner reports. Across all issues, repair costs range from $80 to $18,000. DIY maintenance guides at au7o.io.

All 16 Known Issues

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When Issues Typically Appear

Electric power steering (EPS) assist loss / reduced assist warnings (new body style)

1K-60K

Trailer brake controller / integrated trailer brake module malfunction

5K-90K

A/C condenser leak leading to loss of refrigerant and warm air

20K-90K

Rear axle pinion seal leak and differential fluid loss (AAM 11.5/11.8)

40K-160K

Blend door actuator failure causing temperature/airflow control problems

40K-140K

Transfer case pump rub causing fluid leak and transfer case damage (4WD)

60K-180K

Glow plug control module / glow plug circuit faults causing hard cold starts (Duramax)

60K-180K

050K100K150K200K mi

Frequently Asked Questions

What are the most common GMC Sierra 3500HD problems?

According to Au7o's analysis of 1,600+ owner reports, the 2007-2024 GMC Sierra 3500HD has 16 documented issues. The most frequently reported are: CP4.2 High-Pressure Fuel Pump Catastrophic Failure, Trailer brake controller / integrated trailer brake module malfunction, Transfer case pump rub causing fluid leak and transfer case damage (4WD). Of these, 7 are rated critical and should be addressed promptly.

Is the GMC Sierra 3500HD reliable?

The 2007-2024 GMC Sierra 3500HD has 16 known issues documented across 1,600+ owner reports. 7 issues are rated critical: CP4.2 High-Pressure Fuel Pump Catastrophic Failure and Trailer brake controller / integrated trailer brake module malfunction and Transfer case pump rub causing fluid leak and transfer case damage (4WD) and Electric power steering (EPS) assist loss / reduced assist warnings (new body style) and Allison 1000 Transmission Control Module and Sensor Failures and Diesel Injector Failure Causing White Smoke and Rough Running and Rear Leaf Spring Breakage Under Heavy Loads. 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 3500HD problems?

Repair costs for known GMC Sierra 3500HD issues range from $80 to $18,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, CP4.2 High-Pressure Fuel Pump Catastrophic Failure, typically costs $10,000-$18,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What year GMC Sierra 3500HD is the most reliable?

Reliability varies across model years of the GMC Sierra 3500HD. Based on owner reports, issues are most commonly reported in earlier model years. Au7o recommends checking the specific known issues for your target year before purchasing, and having a pre-purchase inspection performed by a qualified mechanic. Our known issues database covers the 2007-2024 GMC Sierra 3500HD with 16 documented issues from 1,600+ owner reports.