2006 GMC Sierra 1500 Problems: 8 Issues Every Owner Should Know

2006 model year · 0+ owner reports · Updated April 2026

According to Au7o's analysis of 0+ owner reports, the 2006 GMC Sierra 1500 has 8 documented known issues, with 3 rated critical. The most serious are Fuel Pump Module Failure Causing No-Start or Stalling ($500-$1,200 repair), Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure ($800-$2,500 repair) and 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear ($1,800-$3,500 repair). Across all issues, repair costs range from $150 to $3,500. DIY maintenance guides at au7o.io.

All 8 Known Issues

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When Issues Typically Appear

Stepper Motor Instrument Cluster Failure Causing Inaccurate Gauges

50K-150K

Fuel Level Sensor Failure Causing Erratic or Inoperative Gas Gauge

50K-140K

Blend Door / HVAC Actuator Failure Causing Clicking Behind Dash and Incorrect Air Temperature or Mode

50K-180K

Front Hub Bearing Assembly Failure Causing ABS Activation, Noise, and Wheel Play

60K-150K

Knock Sensor Water Intrusion Under Intake Causing Check Engine Light and Reduced Performance

60K-150K

Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure

70K-200K

Fuel Pump Module Failure Causing No-Start or Stalling

80K-180K

4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear

90K-180K

050K100K150K200K mi

On the 2000-2007 GMC Sierra 1500, 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. This issue is widely documented in owner forums and complaint databases across 4.3L, 4.8L, 5.3L, and 6.0L trucks.

This issue also affects: Jeep Grand Wagoneer, Lexus IS, Audi A8

Common Symptoms

long crank before starting
intermittent no-start
engine stalls while driving
loss of power on acceleration
fuel gauge may act erratically if sender/module is failing
whining noise from fuel tank

How to Fix

Diagnosis usually starts with checking fuel pressure at the rail and verifying pump prime at key-on. Low or unstable pressure, especially after sitting, points to a weak pump or failing module. Repair is replacement of the complete fuel pump module and, ideally, the fuel filter on applicable years; corroded electrical connectors at the tank should also be inspected and replaced if heat-damaged.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipConfirm fuel pressure with a mechanical gauge before replacing parts; weak pumps can still be heard priming but fail to meet pressure spec.
TipIf replacing the pump, inspect the tank-side connector for heat damage and replace the pigtail if the terminals are discolored or loose.
UpgradeOwners commonly use a complete OEM-style module rather than a pump-only insert because it also renews the sender and regulator components. (ACDelco GM Original Equipment Fuel Pump Module Assembly)
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UpgradeReplacing the inline fuel filter on applicable GMT800 trucks helps protect the new pump and restore proper flow. (WIX Fuel Filter)
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Typical repair cost:$500 - $1,200

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On the 2003-2007 GMC Sierra 1500, 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 suddenly while driving. GM issued service information and special coverage on many trucks for this exact condition.

This issue also affects: Chevrolet Colorado, Hyundai Elantra, Infiniti FX35

Common Symptoms

fuel gauge reads empty when tank is full
fuel gauge fluctuates while driving
low fuel light comes on incorrectly
distance-to-empty inaccurate
intermittent gauge operation

How to Fix

Confirm the issue by comparing scan-tool fuel level data and observing whether the sender reading jumps erratically. The usual repair is replacement of the fuel level sensor or, more commonly, the entire fuel pump module assembly because of labor overlap and the age of the pump. Connector condition and ground integrity should also be checked during service.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipBecause tank removal labor is the same, many owners replace the complete pump module instead of only the sender on higher-mileage trucks.
TipAvoid repeatedly running the tank very low; owners and technicians often report sender wear and pump overheating are worse when the module is not submerged.
UpgradeA complete module replacement is the most common long-term fix for erratic fuel gauge readings on these trucks. (Delphi Fuel Pump Module Assembly)
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UpgradeAn OEM-style replacement is commonly chosen when owners want factory fit and sender calibration. (ACDelco Fuel Level Sensor / Pump Module Assembly)
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Typical repair cost:$450 - $1,100

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On the 1999-2007 GMC Sierra 1500, 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. The problem is heavily documented in NHTSA complaints and repair forums for GMT800 trucks and related GM full-size pickups.

Common Symptoms

brake pedal suddenly goes to floor
brake fluid leak under truck
reduced braking performance
ABS warning light may illuminate
visible rust and scaling on brake lines

How to Fix

Inspect all hard brake lines from the master cylinder/ABS module to the rear axle and front calipers, paying close attention to flaking rust and wet spots. Spot repairs may buy time, but many owners end up replacing the full line set with pre-bent stainless or coated steel lines because multiple sections are usually compromised. After replacement, the system must be properly bled, including ABS bleed procedures when needed.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipIf one line has burst from rust, inspect the entire system immediately; many owners find the remaining lines are close behind.
TipIn rust-belt trucks, replacing all hard lines at once is often cheaper long-term than repeated patch repairs.
UpgradePre-bent stainless kits are popular because they resist future corrosion better than plain steel replacements. (Dorman Stainless Steel Brake Line Kit)
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UpgradeFresh DOT 3/4 fluid is needed after line replacement and full system bleeding. (Bosch DOT 4 Brake Fluid)
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Typical repair cost:$800 - $2,500

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On the 2000-2007 GMC Sierra 1500, 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.

This issue also affects: Audi S6, BMW 3 Series, BMW 6 Series

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.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipIf rebuilding, owners and transmission builders commonly recommend upgrading to a hardened 'Beast' sun shell rather than reusing stock internals.
TipBefore teardown, verify fluid condition and scan for ratio codes; a worn valve body can mimic some shift complaints but will not restore a broken sun shell.

Typical repair cost:$1,800 - $3,500

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On the 2003-2007 GMC Sierra 1500, 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 stop moving entirely. The problem became widespread enough that GM issued a special coverage adjustment on many trucks and SUVs using the same cluster design.

Common Symptoms

speedometer reads 0 or pegs past 120 mph
fuel gauge inaccurate
oil pressure gauge stuck high or low
tachometer inoperative
intermittent or failed cluster backlighting
warning chimes with incorrect gauge readings

How to Fix

Verify actual vehicle data with a scan tool or GPS speed app to confirm the cluster is inaccurate rather than the sending unit. Repair is typically cluster removal and professional rebuild with updated stepper motors and bulbs, or replacement with a remanufactured unit programmed for the vehicle. If only one gauge is wrong, the whole cluster is still usually rebuilt because the remaining motors often fail later.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipCompare cluster readings to live scan data before replacing sending units; many owners chase false oil pressure or fuel-level problems that are actually cluster-related.
TipUse a rebuilder that installs updated X27.168 stepper motors and tests all gauges, not just the failed one.
UpgradeUpdated stepper motors are the standard fix when rebuilding these GMT800 clusters. (Switec X27.168 Stepper Motor)
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UpgradeMany owners choose a remanufactured cluster to avoid soldering and to get a warranty-backed repair. (Dorman Remanufactured Instrument Cluster)
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Typical repair cost:$250 - $700

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On the 1999-2013 GMC Sierra 1500, 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 or low-speed ABS activation because the wheel speed sensor is integrated into the hub. This is a frequent repair item across both GMT800 and GMT900 generations.

This issue also affects: Chrysler 300, Ford Transit Connect, GMC Yukon XL

Common Symptoms

humming or growling from front end
noise increases with vehicle speed
wheel play or looseness
ABS light on
traction control warning
low-speed ABS activation

How to Fix

Diagnosis involves checking for wheel play with the tire off the ground, listening for bearing noise during road tests, and comparing wheel speed sensor data if ABS symptoms are present. Repair is replacement of the affected hub assembly, and many owners replace both sides if mileage is high. Corrosion at the sensor mounting surfaces and wiring damage should also be addressed to prevent repeat ABS issues.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipIf one front hub is noisy and the other has similar mileage, inspect both sides closely; many owners end up replacing the second hub soon after.
TipAfter hub replacement, verify the ABS harness routing is clipped correctly so it does not rub through on the tire or suspension.
UpgradeOwners often prefer premium hub assemblies because cheap units can be noisy or loose again quickly. (Timken Wheel Bearing and Hub Assembly)
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UpgradeA complete hub with integrated sensor is the standard repair for bearing noise and wheel speed sensor faults. (MOOG Front Wheel Hub Assembly)
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Typical repair cost:$300 - $900

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On the 2000-2006 GMC Sierra 1500, 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 power, especially after washing the engine bay or driving in wet conditions. GM issued service information addressing knock sensor corrosion and revised sealing practices.

This issue also affects: Kia Sorento, Chevrolet Silverado 1500, GMC Yukon XL

Common Symptoms

check engine light
reduced power
poor acceleration
intermittent spark retard
codes return after rain or washing
rough running under load

How to Fix

Diagnosis involves scanning for knock sensor circuit codes, checking freeze-frame data, and inspecting the sensor wells and sub-harness under the intake for moisture or corrosion. Proper repair is replacement of both knock sensors and the harness, cleaning the valley area, and resealing the intake and sensor openings with the updated grommets/sealant procedure to prevent repeat failures.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipReplace both sensors and the sub-harness together; many owners report repeat failures when only one sensor is changed.
TipUse dielectric grease and follow the updated sealing method around the sensor boots to reduce future water intrusion.

Typical repair cost:$400 - $900

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On the 2000-2013 GMC Sierra 1500, 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 the other blows cold. This is one of the most common non-drivetrain complaints on these trucks and is heavily documented in owner forums and repair databases.

This issue also affects: Chevrolet Equinox, GMC Yukon XL, Chevrolet Silverado 1500

Common Symptoms

clicking behind dash
air only blows from defrost
temperature stuck hot or cold
driver and passenger temperatures do not match
mode changes do not respond
recirculation door inoperative

How to Fix

Diagnosis is done by commanding HVAC modes and temperatures while listening for actuator chatter and verifying door movement with a scan tool or visual inspection where accessible. Repair involves replacing the failed mode, blend, or recirculation actuator and then performing HVAC recalibration by fuse pull or scan-tool procedure depending on year and system configuration.

What Owners Are Using

Parts and tips from 0+ owners who fixed this issue

TipIdentify which actuator failed before buying parts; trucks may have separate left, right, mode, and recirculation actuators depending on options.
TipAfter replacement, perform the HVAC recalibration procedure or the new actuator may not index correctly.

Typical repair cost:$150 - $700

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Frequently Asked Questions

What are the most common GMC Sierra 1500 problems?

According to Au7o's analysis of 0+ owner reports, the 2006-2006 GMC Sierra 1500 has 8 documented issues. The most frequently reported are: Fuel Pump Module Failure Causing No-Start or Stalling, Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure, 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear. Of these, 3 are rated critical and should be addressed promptly.

Is the GMC Sierra 1500 reliable?

The 2006-2006 GMC Sierra 1500 has 8 known issues documented across 0+ owner reports. 3 issues are rated critical: Fuel Pump Module Failure Causing No-Start or Stalling and Rusting Brake Lines Leading to Fluid Loss and Sudden Brake Failure and 4L60-E / 4L65-E Sun Shell Failure Causing Loss of Reverse and 2nd/4th Gear. 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, Fuel Pump Module Failure Causing No-Start or Stalling, typically costs $500-$1,200 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

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 2000-2007 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 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.

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 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 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 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.

All 8 Known Issues

When Issues Typically Appear

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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

Common Symptoms

How to Fix

What Owners Are Using

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Other GMC Models

Frequently Asked Questions

What are the most common GMC Sierra 1500 problems?

Is the GMC Sierra 1500 reliable?

How much does it cost to fix common GMC Sierra 1500 problems?

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

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

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

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

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

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

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

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