Is Your Hummer H2 Running Rough, Stalling, or Refusing to Start?
As a mechanic with over two decades of experience, I’ve seen countless GM trucks and SUVs, including the mighty Hummer H2, sidelined by a faulty Powertrain Control Module (PCM). The symptoms can be maddening and often lead to replacing perfectly good parts. If you’re dealing with persistent check engine lights, erratic transmission shifting, poor fuel economy, or a no-start condition that has you stumped, the PCM is a very likely culprit. This isn’t just a part; it’s the brain of your vehicle, and when it fails, it can cause chaos.
From the Shop Floor: “A customer’s ’05 Hummer H2 came in last week with a no-start condition that two other shops couldn’t figure out. They had already replaced the fuel pump and crank sensor. After checking the basics, we hooked up our scope and found the PCM wasn’t firing the fuel injectors on one bank. It’s a classic internal failure I’ve seen dozens of times on these P59 controllers, usually caused by years of heat cycles under the hood. A new, correctly programmed PCM had them back on the road in under an hour.”
The Direct Solution: A Pre-Programmed 2003-2007 HUMMER H2 PCM
Don’t waste time and money chasing ghosts in the electrical system. This Powertrain Control Module is a direct-fit replacement, arriving at your door fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We install the latest GM-certified software updates, which often correct drivability issues the original factory programming had. This ensures your H2 runs exactly as the manufacturer intended, restoring lost power and efficiency.
Key Symptoms of a Failing GM PCM:
- โ Unexplained Check Engine Light (with codes for sensors you’ve already replaced)
- โ Vehicle will not start or stalls intermittently
- โ Harsh or erratic automatic transmission shifting
- โ Noticeable decrease in fuel mileage
- โ Communication errors with diagnostic scan tools
- โ Failure of one or more fuel injectors or ignition coils to operate
Plug-and-Play Installation: No Dealer Visit Required
One of the biggest advantages of our service is the VIN programming. This module is ready to install right out of the box, with no need for expensive dealership programming or special tools. Just follow these simple steps to get your H2 running right again.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: On most 2003-2007 Hummer H2 models, the PCM is located in the engine bay on the driver’s side, under the battery tray. You will likely need to remove the battery to access it.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. Inspect the connectors for any signs of corrosion or bent pins and clean them if necessary.
- Remove Old Module: Unbolt the old PCM from its mounting bracket.
- Install New Module: Bolt the new, pre-programmed PCM into place and securely reconnect the wiring harnesses. You should hear a distinct click.
- Reconnect Battery: Reinstall the battery and connect the negative terminal.
- Perform Security Relearn (If Necessary): In most cases, the vehicle will start and run perfectly. Some vehicles may require a simple 10-30 minute key-cycle security relearn procedure. Instructions are included, and it requires no tools.
Guaranteed Compatibility
This module, part number 12589463, is a direct replacement for several service numbers. Please verify your original part number matches one of the following to ensure compatibility: 89017750, 12582605, 12589463, 12602802, 89017734, 28042802. This unit fits a wide range of GM trucks and SUVs beyond the Hummer H2, including many popular Chevrolet, GMC, Cadillac, and Isuzu models from 2003 to 2007. Simply provide your VIN at checkout, and we’ll handle the rest.