The 2009 H2 rides on GM's GMT900 truck platform with either the 6.0L or 6.2L V8. While mechanically robust in many ways, these trucks suffer from Active Fuel Management failures, transmission cooling issues, and notorious fuel system headaches that can strand you.
AFM (Active Fuel Management) Lifter and Cam Failure
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Check engine light with P0300-series misfire codes or P0521 oil pressure, Lifter tick or tapping noise on cold start that persists, Loss of power, rough idle, cylinder deactivation malfunction, Metal debris in oil during changes
Fix: AFM lifters collapse and damage cam lobes. Requires heads-off teardown, replace all lifters, camshaft, sometimes valve springs and pushrods. Delete AFM with aftermarket non-AFM cam or live with risk of repeat failure. 18-24 labor hours depending on how deep the damage goes.
Estimated cost: $3,500-6,500
Transmission Oil Cooler Line Failure and Fluid Cross-Contamination
Common · high severityTypical onset: 70,000-120,000 mi
Symptoms: Transmission slipping or delayed engagement, Milky or strawberry-milkshake appearance in coolant reservoir, Engine overheating combined with transmission issues, Low transmission fluid with no visible external leak
Fix: Internal cooler in radiator fails, allowing coolant into trans fluid or vice versa. Requires new radiator, complete transmission flush (sometimes full rebuild if damage occurred), cooler lines. If contamination sat, trans is toast. 8-12 hours labor for cooler and flush; add 15-20 hours if trans rebuild needed.
Estimated cost: $1,200-2,500 (cooler/flush) or $3,500-5,000 (if trans rebuild required)
Fuel Pump and Fuel Level Sender Failure
Common · high severityTypical onset: 60,000-110,000 mi
Symptoms: No-start or stalling, especially when tank below half, Fuel gauge reading erratically or stuck on empty/full, Engine stumbling or cutting out during acceleration, Whining noise from fuel tank area
Fix: Pump module assembly fails; sender units are known weak points on GMT900. Requires dropping 32-gallon fuel tank, replacing entire pump module. Work is tedious due to tank size and skid plate removal. 4-5 hours labor.
Estimated cost: $800-1,400
Transfer Case Encoder Motor and Mode Shift Issues
Occasional · medium severityTypical onset: 70,000-130,000 mi
Symptoms: Service 4WD message on dash, Unable to shift into or out of 4WD modes, Grinding or clunking when attempting mode changes, Blinking 4WD indicator lights
Fix: Encoder motor on NP246 transfer case wears out or position sensor fails. Sometimes just motor replacement, sometimes internal mode fork or chain issues require case teardown. Motor alone: 2-3 hours. Full internal work: 8-10 hours.
Estimated cost: $600-1,200 (motor) or $1,800-3,000 (internal repair)
EBCM (Electronic Brake Control Module) Failure
Occasional · high severityTypical onset: 90,000-140,000 mi
Symptoms: ABS, traction control, and StabiliTrak lights all illuminated, Loss of ABS and stability control function, Codes C0265, C0267, or pump motor circuit codes, Sometimes causes firm brake pedal with reduced assist
Fix: EBCM or internal pump motor fails. Module is integrated with ABS pump; requires complete assembly replacement and bleeding. Some units available remanufactured. 3-4 hours labor including bleed and setup.
Estimated cost: $1,200-2,200
Exhaust Manifold Bolt Breakage and Manifold Cracking
Occasional · medium severityTypical onset: 80,000-150,000 mi
Symptoms: Loud exhaust ticking or tapping from engine bay, worse on cold start, Exhaust smell in cabin or under hood, Visible soot streaks on manifolds, Check engine light with O2 sensor codes
Fix: Cast iron manifolds crack or mounting bolts break due to heat cycling. Bolts often break flush in head, requiring extraction. Both sides common. Remove manifolds, extract broken bolts, resurface head flange if warped, new gaskets and Grade 8 bolts. 6-8 hours per side.
Estimated cost: $800-1,600 per side
A/C Compressor Clutch and Condenser Failure
Occasional · low severityTypical onset: 70,000-120,000 mi
Symptoms: A/C blows warm intermittently or constantly, Compressor clutch not engaging or cycling rapidly, Front condenser leaking refrigerant (check for rock damage), Squealing from compressor area
Fix: Clutch coil or bearing fails, or front condenser gets punctured from road debris. Compressor replacement: 3-4 hours. Condenser: 4-5 hours due to grille and bumper removal. System requires evacuation, component swap, and recharge.
Estimated cost: $900-1,600
Buy only if you can wrench yourself or have a $3K repair fund — AFM and trans cooler issues are not 'if' but 'when,' and parts/labor costs reflect full-size truck pricing.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.