GM is receiving damaged (cracked or broken) transmission cores returned to the reman facilities. The damage is being caused either in the removal process by the technician, or inadequate packaging or shipping. This bulletin advises the dealers to be more careful not to damage the transmissions during removal and to package the core properly for return.
full bulletin at NHTSA ↗2006 GMC Envoy powertrain problems
severe 19 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
19
Recalls
0
Avg fix
$2,500
2fires
When does it fail?
Of the 19 powertrain complaints filed for the 2006 GMC Envoy, here's the actual mileage breakdown — failures cluster heaviest at 100,000-125,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA powertrain complaint has been filed on this vehicle in over 7 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
full bulletin at NHTSA ↗This Warranty Admin service bulletin provides guidelines for Dealers Not Required and for Dealers Required to Contact the PQC for engine or transmission assembly replacement and explains the PQC process, GWM Transaction submission, vehicle service record retention and proper handling of assembly returns for Canadian Dealers only.
full bulletin at NHTSA ↗This PI bulletin advises the technician on the proper way to install the pistons in an engine.
full bulletin at NHTSA ↗This service bulletin provides a vibration analysis worksheet the technician can use in conjunction with the appropriate Vibration Analysis-Road testing procedure when diagnosing vibration concerns.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Transmission failures dominate this complaint cluster. Owners report complete loss of drive capability starting around 56,000 to 131,000 miles—vehicles refuse to accelerate from stops, shift into limp mode, or lock completely. One owner lost 2nd and 4th gears; another found only manual gear selection would move the truck.
The plastic shift linkage connecting the shifter to the transmission input lever is a recurring failure point. Multiple owners had linkages separate, leaving them unable to shift into any gear or properly park. One owner discovered the connection made entirely of plastic after it snapped during a school parking lot incident.
Engine shutdown while driving is another critical failure. Vehicles die mid-drive with no power steering or braking. One owner traced it to a faulty ignition switch; another's dealer found improper factory wiring routing at the firewall causing abrasion and electrical shorts.
Reduced Engine Power mode kicks in unexpectedly, cutting acceleration and forcing emergency maneuvers. Owners have replaced throttle bodies, gas pedal sensors, and PCMs with no resolution. The problem worsens in cold or wet weather.
One owner experienced a front differential failure that sprayed lubricant onto the catalytic converter, igniting a fire on the highway. GM investigators confirmed the defect but refused to break the lease.
Four-wheel drive encoder motor failures recur, leaving owners stranded in serious weather. Transmission whining and design-flaw squealing in overdrive round out the reported issues.
Same GMC Envoy powertrain reports on nearby years: 2005
Failure modes owners describe
Transmission complete failure / loss of drive
Transmission loses ability to move vehicle forward, shifts into limp mode, or fails completely. Owners report inability to accelerate from stops, loss of multiple gears, or dead transmission requiring replacement.
When: 94,500 miles, 131,000 miles, 56,000 miles reported; can occur early in ownership
Symptoms owners cite: No power delivery when placed in Drive; Vehicle rolls slowly or only moves in manual gear selection; Complete failure to accelerate from intersection or stop; Loss of 2nd and 4th gears; Transmission locked in Park after stall
Codes mentioned: P1516, P1682
Repairs/costs cited: Transmission replacement required; owners report dealership diagnosis at independent shops
Shifter linkage separation / plastic failure
The plastic connector linking the shifter to transmission input lever separates or breaks. Owner discovered linkage separated underneath vehicle after transmission would not respond to shifter input. Multiple owners report plastic shift linkage components breaking.
When: Timing not specified; owner found linkage separated during parking incident
Symptoms owners cite: Shifter does not respond to driver input; Vehicle does not park properly and continues to roll; Shifter button will not depress after vehicle shutdown; Vehicle cannot be shifted into any gear
Repairs/costs cited: Reconnection of linkage; owner notes the connector appears to be made from plastic and is inadequate for the function
Engine shutdown while driving / ignition switch failure
Engine dies unexpectedly while vehicle is in motion, disabling power steering, power braking, and ability to restart. One owner pinpointed faulty ignition switch as cause; another traced electrical short in factory wiring at firewall causing transmission to lock in Park.
When: 30,000 miles; less than 30k miles for ignition switch failure case; one incident in May 2009
Symptoms owners cite: Engine dies completely while driving; Vehicle will not restart immediately; Loss of power steering and power braking; Shifter locked and cannot move to Neutral; Warning lights dim and scroll on display; Transmission locks in Park, preventing push-start
Codes mentioned: P1516, P1682
Repairs/costs cited: One owner replaced ignition switch (~$30 part) and vehicle operated normally; another owner's dealer found electrical short in factory wiring under dashboard at firewall/brake booster area caused by improper routing and abrasion over time
Recalls/TSBs owners mention: GMC claimed engine shutdown during driver-side door smoking incident was a designed safety feature
Reduced Engine Power mode / throttle body / sensor faults
Vehicle enters reduced engine power mode unexpectedly, cutting acceleration and requiring emergency maneuvers. Multiple owners report issue related to throttle body, gas pedal sensor, or electronic throttle control. Problem often intermittent and worsens in cold/wet conditions.
When: Timing varies; one incident at 10,000 miles for cold start; intermittent throughout ownership
Symptoms owners cite: Reduced Engine Power light and MIL light illuminate; Loss of acceleration capability; Check engine light on and off; Rough idle; Speed reduction on display; Stabilitrak OFF message displayed; More frequent in cold or wet conditions; Pinging sound from engine under load after repair attempt
Codes mentioned: P0014, P2135, P0121, P060E
Repairs/costs cited: Throttle body cleaning attempted; throttle body replacement attempted; gas pedal sensor replacement attempted; PCM replacement attempted—owner reports problem persists after multiple service attempts
Front differential failure / fire
Front differential failed, causing lubricant to spray onto catalytic converter and exhaust system, which ignited a fire on the highway. General Motors investigator confirmed defect. GM refused to break lease and offered only repair.
When: During highway driving; unclear mileage
Symptoms owners cite: Fire visible under engine compartment; Flames and smoke underneath vehicle
Repairs/costs cited: Towed to dealership; GM investigator confirmed differential failure
Recalls/TSBs owners mention: GM admitted defect, offered repair and refused to break lease or remove vehicle from service
Four-wheel drive encoder motor / wiring failure
Four-wheel drive system fails to engage, particularly in poor weather when needed. Failure traced to encoder motor and wiring, recurring issue. Owner reports fourth failure within roughly four years.
When: First failure February 15, 2010; recurring failures through February 2014; fourth failure in serious weather conditions
Symptoms owners cite: 4WD not operating in adverse weather conditions; System failure when actively needed
Repairs/costs cited: Decoder motor and wiring replaced; same problem recurs
Abrupt transmission shift to 1st gear after stopping
Transmission shifts abruptly into 1st gear immediately after vehicle comes to complete stop, creating sensation of impact from behind. Intermittent but recurring issue.
When: Beginning around 10,000 miles
Symptoms owners cite: Abrupt downshift into 1st gear after coming to stop; Feels like vehicle has been hit from behind; Happens frequently but not every time
Recalls/TSBs owners mention: Dealer unable to duplicate problem but states other owners have reported same issue
Transmission whining noise
Loud whining noise emanates from transmission during operation. Failure mode and cause unknown; vehicle not repaired by owner.
When: 30,000 miles
Symptoms owners cite: Loud whining noise from transmission
Repairs/costs cited: Vehicle not repaired
Transmission overdrive noise / design flaw
Constant squealing noise from rear when vehicle is in overdrive. Dealership attributed to design flaw with no available fix and recommended avoiding overdrive. Noise worsens over time.
When: Timing not specified
Symptoms owners cite: Constant squeal from rear in overdrive; Noise progressively gets louder over time
Recalls/TSBs owners mention: Dealership stated it is a design flaw and advised not to drive in overdrive; no repair available
Synthesized from 19 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
Radiator and transmission went while driving on a highway. My mechanic told me the part that failed never fails and he was shocked that it did.
Had powertrain trouble with your 2006 GMC Envoy?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2006 GMC Envoy?
It's a meaningful issue. 19 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Across the 16 complaints that reported odometer mileage, most powertrain failures cluster between 34,961 and 118,000 miles, with the median around 80,150. A quarter of owners report trouble before 34,961; a quarter make it past 118,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2006/GMC/Envoy.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.