GMC · Known Issues

2006 GMC Sierra 1500 Problems: 8 Known Issues

2006 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated August 2026

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 GMC Sierra 1500 has 8 documented known issues, with 3 rated critical. The most serious are 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear ($1,800-$3,500 repair), Fuel Pump Module Failure Causing No-Start or Stalling ($500-$1,200 repair) and Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure ($800-$2,500 repair). Across all issues with published estimates, repair costs range from $150 to $3,500. DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common GMC Sierra 1500 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 GMC Sierra 1500 has 8 documented issues. The most frequently reported are: 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear, Fuel Pump Module Failure Causing No-Start or Stalling, Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure. Of these, 3 are rated critical and should be addressed promptly.

Is the GMC Sierra 1500 reliable?

The 2006 GMC Sierra 1500 has 8 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 3 issues are rated critical: 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear and Fuel Pump Module Failure Causing No-Start or Stalling and Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure. 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 1500 problems?

Repair costs for known GMC Sierra 1500 issues range from $150 to $3,500, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear, typically costs $1,800-$3,500 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2000-2007 GMC Sierra 1500 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear?

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 fl… Repairs typically run $1,800-$3,500. Severity: high.

What is the 2000-2007 GMC Sierra 1500 Fuel Pump Module Failure Causing No-Start or Stalling?

A common GMT800 Sierra problem is failure of the in-tank fuel pump module, often from worn pump motors or failed level-sender/module electronics. Owners report long crank, hard starting, loss of power under load, or sudden stall/no-start conditions, especially as mileage climbs. Repairs typically run $500-$1,200. Severity: high.

What is the 1999-2007 GMC Sierra 1500 Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure?

Corrosion of steel brake lines is a major safety issue on older Sierra 1500 trucks, especially in salt-belt states. Owners report the brake pedal suddenly dropping to the floor when a rusted line bursts during normal braking, often near the ABS module or along the frame rails. Th… Repairs typically run $800-$2,500. Severity: high.

What is the 2000-2013 GMC Sierra 1500 Blend Door / HVAC Actuator Failure Causing Clicking Behind Dash and Incorrect Air Temperature or Mode?

Sierra owners across both GMT800 and GMT900 generations frequently report small electric HVAC actuators stripping internal gears or losing calibration. The result is a repetitive clicking or tapping noise from the dash, air stuck on defrost or floor, or one side blowing hot while… Repairs typically run $150-$700. Severity: medium.

What is the 1999-2013 GMC Sierra 1500 Front Hub Bearing Assembly Failure Causing ABS Activation, Noise, and Wheel Play?

Front wheel hub bearing assemblies on Sierra 1500 trucks commonly wear out, especially on 4WD models and trucks used with larger tires or in rough conditions. Owners report humming or growling that changes with speed, looseness in the front wheel, and in some cases ABS warnings o… Repairs typically run $300-$900. Severity: medium.

What is the 2003-2007 GMC Sierra 1500 Fuel Level Sensor Failure Causing Erratic or Inoperative Gas Gauge?

A very common GMT800 complaint is sulfur contamination and wear of the fuel level sensor contacts inside the tank module, causing the gauge to read empty, full, or fluctuate unpredictably. Owners often see a low-fuel warning with plenty of fuel in the tank or watch the gauge drop… Repairs typically run $450-$1,100. Severity: medium.

What is the 2000-2006 GMC Sierra 1500 Knock Sensor Water Intrusion Under Intake Causing Check Engine Light and Reduced Performance?

The 4.8L, 5.3L, and 6.0L Vortec engines used in early GMT800 Sierra trucks place the knock sensors in wells beneath the intake manifold, where water can collect and corrode the sensors or harness. Owners frequently report recurring check-engine lights, timing retard, and reduced… Repairs typically run $400-$900. Severity: medium.

What is the 2003-2007 GMC Sierra 1500 Stepper Motor Instrument Cluster Failure Causing Inaccurate Gauges?

2003-2007 Classic-era Sierra trucks are well known for instrument cluster gauge failures caused by defective stepper motors and, in some cases, backlighting issues. Speedometer, tachometer, oil pressure, fuel, voltage, and coolant gauges can stick, read wildly high or low, or sto… Repairs typically run $250-$700. Severity: medium.

All 8 Known Issues

When Issues Typically Appear

2000-2007 GMC Sierra 1500: Fuel Pump Module Failure Causing No-Start or Stalling#

2003-2007 GMC Sierra 1500: Fuel Level Sensor Failure Causing Erratic or Inoperative Gas Gauge#

2000-2007 GMC Sierra 1500: 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear#

1999-2007 GMC Sierra 1500: Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure#

2000-2013 GMC Sierra 1500: Blend Door / HVAC Actuator Failure Causing Clicking Behind Dash and Incorrect Air Temperature or Mode#

1999-2013 GMC Sierra 1500: Front Hub Bearing Assembly Failure Causing ABS Activation, Noise, and Wheel Play#

2000-2006 GMC Sierra 1500: Knock Sensor Water Intrusion Under Intake Causing Check Engine Light and Reduced Performance#

2003-2007 GMC Sierra 1500: Stepper Motor Instrument Cluster Failure Causing Inaccurate Gauges#

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