Restore Peak Performance to Your GM Truck or SUV
Is your 2003-2007 Hummer H2, Silverado, or Sierra suddenly running rough, refusing to start, or throwing confusing check engine light codes? As a technician with over two decades of experience, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can turn a reliable workhorse into a source of constant frustration. The PCM is the brain of your vehicle, managing everything from fuel injection and spark timing to transmission shifts. When it falters, the symptoms can be unpredictable and difficult to diagnose.
This isn’t just a replacement part; it’s a direct solution. We take the guesswork and dealership hassle out of the equation. Each module, including part number 89017750, is meticulously programmed to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This process ensures it arrives loaded with the latest GM factory software updates, often correcting underlying drivability issues you may not have even realized were software-related. You get a reliable, plug-and-play fix designed to restore the original performance and efficiency of your engine.
Is Your Truck Showing These PCM Failure Signs?
A faulty PCM can manifest in numerous ways. If you’re experiencing any of the following, a failing computer could be the culprit. I’ve seen these symptoms countless times in my diagnostic bay:
- ✔ Check Engine Light is on with communication codes like U0100 or internal processor failure codes like P0601 or P0606.
- ✔ The engine cranks but refuses to start, or starts intermittently.
- ✔ Noticeable decrease in fuel economy for no apparent reason.
- ✔ Harsh, erratic, or delayed transmission shifting.
- ✔ Engine stalling, sputtering, or running rough at idle or under load.
- ✔ Vehicle is in “limp mode,” with reduced power.
Case Study: A Tricky Diagnosis
I remember a 2006 Hummer H2 that came into the shop with a maddeningly intermittent no-start condition. The owner had already replaced the battery and checked the fuel pump. It would start fine for a week, then leave him stranded. All the basic checks were passing. After hooking up my scan tool and monitoring live data, I noticed that when the engine bay got hot, the PCM would occasionally stop communicating with the other modules. We let the truck cool down, and it would start right up. The internal circuits of the original PCM were failing under heat soak—a classic sign of age-related failure. Installing a quality, pre-programmed 2003-2007 HUMMER H2 PCM solved the problem for good, saving the customer from more wasted time and diagnostic fees.
Your Step-by-Step PCM Installation Guide
Installing your new 2003-2007 HUMMER H2 PCM is a straightforward job for a confident DIYer. Taking your time and following these steps will ensure a smooth swap.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental power surges.
- Locate the PCM: On most of these GM trucks and SUVs, including the Hummer H2, the PCM is located in the engine bay on the driver’s side, typically under or next to the battery tray. You may need to remove the battery to gain access.
- Disconnect the Connectors: The PCM will have several large wiring harness connectors. These connectors have locking levers or tabs. Carefully release the locks and gently pull the connectors straight out from the module. Never force them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Seat your new, pre-programmed PCM into the mounting bracket and secure it. Reconnect the wiring harnesses, ensuring they click securely into place and the locking levers are fully engaged.
- Final Steps: Reinstall the battery (if removed) and reconnect the negative battery terminal. In many cases, the vehicle will start and run perfectly. However, some vehicles may require a security relearn procedure (often called a Passlock or Passkey relearn), which can typically be done without special tools. Instructions are readily available online for your specific model.
Verified Fitment For These GM Trucks & SUVs
This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802, and fits a wide range of vehicles. Please verify your model and year below:
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. This PCM arrives at your door fully programmed to your vehicle’s VIN with the latest GM software. It is ready for installation right out of the box. The only additional step that may be required on some vehicles is a simple security relearn procedure.
How do I provide my VIN number?
After you complete your purchase, you will need to send us a message with your 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your driver’s side dashboard (visible through the windshield) or on the driver’s side door jamb sticker.
Will this fix my hard shifting transmission?
In many cases, yes. The PCM controls transmission line pressure and shift points. If the module is failing, it can cause erratic or harsh shifting. A new, correctly programmed PCM often resolves these types of transmission issues.
What is a CASE Relearn and will I need one?
A CASE (Crankshaft Angle Sensor Error) Relearn synchronizes the crankshaft position sensor with the PCM. While not always required after a PCM swap, a professional scan tool is needed to perform it. If you have a persistent P0315 code after installation, a CASE relearn may be necessary.
Is this compatible with other part numbers?
Yes, this unit is a direct replacement for several service numbers, including 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. If your original module has one of these numbers, this part is compatible.