Restore Peak Performance to Your GM Truck or SUV
Is your HUMMER H2, Silverado, or Sierra plagued by frustrating issues like a persistent Check Engine Light, rough idling, stalling, or poor fuel economy? These are classic signs of a failing Powertrain Control Module (PCM), the central computer of your vehicle’s engine and transmission. Don’t let a faulty computer keep you off the road. This direct-fit replacement PCM, part number 12582605, is the reliable solution to restore your truck’s power, efficiency, and drivability.
Unlike sourcing a part from a junkyard or a generic retailer, we provide a crucial service: each module is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN). This ensures seamless communication with all other onboard systems and installs the latest GM software updates, often correcting factory flaws you never knew you had. This is the key to a lasting, effective repair.
From the Diagnostic Bay
I remember a 2005 HUMMER H2 that came into my shop with a maddeningly intermittent no-start condition. The owner had already replaced the battery, starter, and even the ignition switch. The truck would crank but wouldn’t fire, and then, an hour later, it would start like nothing was wrong. There were no consistent trouble codes, just a generic U0100 ‘Lost Communication with ECM/PCM’ that would pop up occasionally. After checking all the power and ground circuits to the PCM connectors, we found they were solid. On a hunch, we gently tapped on the PCM housing while an assistant cranked the engine, and it fired right up. This pointed to an internal failure—a cracked solder joint on the main processor that would lose connection when it cooled down. Replacing the module with a pre-programmed unit like this one solved the problem permanently. It’s a textbook example of how a failing 2003-2007 HUMMER H2 PCM can create phantom issues that are tough to trace.
Is Your Vehicle Exhibiting These Failure Symptoms?
A failing PCM can cause a wide range of problems. If you’re experiencing any of the following, your engine computer is the likely culprit:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error), P0606 (ECM/PCM Processor Fault), or communication errors (U-codes).
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained stalling or rough, erratic idling.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Harsh or incorrect transmission shifting.
- ✔ Apparent loss of engine power and poor acceleration.
A Straightforward Guide to Installation
For the confident DIYer, replacing the PCM is a manageable job that requires basic hand tools. This pre-programmed module makes the process much simpler, eliminating the need for expensive dealer tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On most HUMMER H2 and similar GM trucks, the PCM is located in the engine bay on the driver’s side, often under the battery tray or next to the air filter box. You may need to remove the battery and its tray for access.
- Disconnect the Harnesses: Carefully disengage the locking levers on the electrical connectors. They can be stiff, so apply steady pressure. Pull the connectors straight out from the module. Inspect them for any corrosion or bent pins.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s typically held in by a few small bolts.
- Install the New Module: Mount your new PCM onto the bracket and securely fasten it. Reconnect the electrical harnesses, ensuring the locking levers click firmly into place.
- Final Steps: Reinstall the battery tray and the battery, then reconnect the negative battery terminal. Your vehicle may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for specific instructions.
Guaranteed Fitment for Your GM Truck or SUV
This 2003-2007 HUMMER H2 PCM is a direct replacement for a wide array of General Motors vehicles. It is compatible with service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. Please verify your vehicle from the list below. If your vehicle requires ID 12602802, this module is a correct replacement.
- HUMMER H2: 2003, 2004, 2005, 2006, 2007
- Cadillac Escalade, ESV, EXT: 2003-2006
- Chevrolet Avalanche 1500: 2003-2006
- Chevrolet Silverado 1500, 2500, 3500: 2003-2007 (Classic Style)
- Chevrolet Suburban 1500, 2500: 2003-2006
- Chevrolet Tahoe: 2003-2006
- Chevrolet SSR: 2003
- GMC Envoy XL: 2003
- GMC Sierra 1500, 2500, 3500, Denali: 2003-2007 (Classic Style)
- GMC Yukon, Yukon XL 1500, Yukon XL 2500: 2003-2006
- Isuzu Ascender: 2003
- Chevrolet Trailblazer EXT: 2003
Frequently Asked Questions
What do I need to do after I purchase this PCM?
After your purchase, simply reply to your order confirmation email with your vehicle’s 17-digit VIN. We need this to program the module with the correct, updated GM software for your specific vehicle before we ship it.
Will I need to have a dealer program this module?
No. This module arrives at your door fully programmed and ready for installation. This plug-and-play solution saves you the time, cost, and hassle of a trip to the dealership for programming.
Where is the PCM located on my 2004 HUMMER H2?
On the 2003-2007 HUMMER H2, the PCM is typically found in the engine compartment on the driver’s side, mounted to a bracket underneath the battery tray.
My part number is 89017750. Will this work?
Yes. This PCM, part number 12582605, is a direct, compatible replacement for several service numbers, including 89017750, 12589463, and 12602802, among others listed in the description.
Does this PCM require a security or CASE relearn?
In most cases, a simple security relearn (often called a ‘key-on’ procedure) is all that’s needed, which you can do yourself. In some instances, a Crankshaft Variation (CASE) relearn may be required to clear a P1336 code, which can be performed with a capable bi-directional scan tool.