If your 2003-2007 GMC Sierra or compatible GM truck is giving you headaches with erratic behavior, poor fuel economy, or a persistent Check Engine Light, the problem often lies with the brain of the operation: the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen countless vehicles sidelined by a failing PCM. It’s a frustrating issue that can manifest as anything from a no-start condition to bizarre transmission shifting, leaving owners chasing symptoms without finding the root cause.
This isn’t just a replacement part; it’s a direct solution. We provide a high-quality PCM, part number 12602802, that is professionally programmed to your truck’s specific Vehicle Identification Number (VIN). This critical step ensures all factory settings, security information, and operational parameters are perfectly matched to your vehicle. We load the latest, most stable software updates from GM, which can resolve underlying drivability issues you may not have even realized were software-related. Forget the hassle and expense of towing your truck to a dealership for programming—this module arrives ready for installation.
Case Study: The Ghost in the Machine
I remember a 2005 Silverado that came into my bay with a list of intermittent complaints. The owner was frustrated; he’d replaced sensors and plugs, but the truck would still occasionally stall at idle and shift hard from first to second. No consistent codes were stored, just a history of random communication errors. After verifying the wiring harnesses were solid, we focused on the PCM. On the surface, it seemed fine, but under load, the processor was failing. Swapping in a VIN-programmed 2003-2007 Sierra 1500 PCM like this one didn’t just fix the stalling—it smoothed out the shifting and even improved the throttle response. It was a night-and-day difference.
Is Your Truck Showing These Signs of a Failing PCM?
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle stalls for no apparent reason, either while driving or at idle.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Your PCM Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle in their own driveway. With our pre-programmed module, you skip the hardest part. Follow these steps for a successful installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
- Locate the PCM: On most of these trucks and SUVs, you’ll find the PCM in the engine bay on the driver’s side, typically under or next to the battery tray.
- Disconnect the Connectors: Carefully unplug the wiring harness connectors from the old PCM. These usually have a lever or tab that needs to be moved to release them. Avoid forcing them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new unit.
- Install the New PCM: Mount the new, programmed PCM and securely plug in the wiring harness connectors. You should hear a click as they lock into place.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Security Relearn: You will likely need to perform a security relearn procedure (often called a Passlock or Passkey relearn) to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM trucks and SUVs. It is compatible with service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. Please verify your part number or consult the fitment list below. Note that for some 2004 models, matching the ID 12602802 is critical.
ESCALADE 04 Electronic Control Module; (LH front under battery), ID 12602802
ESCALADE EXT 04 Electronic Control Module; (LH front under battery), ID 12602802
HUMMER H2 04 Electronic Control Module; (LH front under battery), SUV
SIERRA 3500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
TAHOE 04 Electronic Control Module; (LH front under battery), ID 12602802
YUKON XL 2500 04 Electronic Control Module; (LH front under battery), 6.0L, ID 12602802
ENVOY XL 03 Electronic Control Module; 5.3L (next to air box)
SUBURBAN 2500 03 Electronic Control Module; (LH front under battery), 6.0L
YUKON 04 Electronic Control Module; (LH front under battery), ID 12602802
YUKON XL 2500 05-06 Electronic Control Module; (LH front under battery), 6.0L
AVALANCHE 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
SIERRA 1500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), w/o hybrid option; w/o 4.3L
SIERRA DENALI 05-06 Electronic Control Module; (LH front under battery)
SUBURBAN 2500 04 Electronic Control Module; (LH front under battery), 6.0L, ID 12602802
YUKON XL 1500 03 Electronic Control Module; (LH front under battery)
YUKON XL 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
ESCALADE ESV 03 Electronic Control Module; (LH front under battery), PCM
ESCALADE ESV 04 Electronic Control Module; (LH front under battery), ID 12602802
HUMMER H2 07 Electronic Control Module; (LH front under battery), powertrain control
SIERRA 3500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SIERRA DENALI 03 Electronic Control Module; (LH front under battery)
SILVERADO 2500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 03 Electronic Control Module; (LH front under battery)
HUMMER H2 05-06 Electronic Control Module; (LH front under battery)
SIERRA 2500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
YUKON 03 Electronic Control Module; (LH front under battery)
ESCALADE 05-06 Electronic Control Module; (LH front under battery)
ESCALADE ESV 05-06 Electronic Control Module; (LH front under battery)
AVALANCHE 1500 03 Electronic Control Module; (LH front under battery)
SILVERADO 2500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SILVERADO 1500 PICKUP 04 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L; ID 12602802
TAHOE 03 Electronic Control Module; (LH front under battery)
TAHOE 05-06 Electronic Control Module; (LH front under battery)
YUKON 05-06 Electronic Control Module; (LH front under battery)
SILVERADO 3500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
SILVERADO 2500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SILVERADO 3500 PICKUP 05-06 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 04 Electronic Control Module; (LH front under battery), ID 12602802
ISUZU ASCENDER 03 Electronic Control Module; (LH engine), 5.3L
SIERRA 1500 PICKUP 03-04 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L
ESCALADE 03 Electronic Control Module; (LH front under battery), PCM
SSR 03 Electronic Control Module; (next to air box)
SIERRA DENALI 07 Electronic Control Module; classic style (creased door skin), (LH front under battery)
SILVERADO 3500 PICKUP 03 Electronic Control Module; (LH front under battery), gasoline, 6.0L
SUBURBAN 1500 05-06 Electronic Control Module; (LH front under battery)
TRAILBLAZER EXT 03 Electronic Control Module; 5.3L (next to air box)
SILVERADO 1500 PICKUP 05-07 Electronic Control Module; classic style (creased door skin), (LH front under battery), w/o hybrid option; w/o 4.3L
SILVERADO 3500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
YUKON XL 1500 05-06 Electronic Control Module; (LH front under battery)
ESCALADE EXT 05-06 Electronic Control Module; (LH front under battery)
SIERRA 1500 PICKUP 05-06 Electronic Control Module; (LH front under battery), w/o hybrid option; w/o 4.3L
SUBURBAN 2500 05-06 Electronic Control Module; (LH front under battery), 6.0L
HUMMER H2 03 Electronic Control Module; (LH front under battery)
SIERRA 2500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SIERRA 3500 PICKUP 07 Electronic Control Module; classic style (creased door skin), (LH front under battery), gasoline, 6.0L
SIERRA DENALI 04 Electronic Control Module; (LH front under battery), ID 12602802
ESCALADE EXT 03 Electronic Control Module; (LH front under battery), PCM
SIERRA 3500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
SILVERADO 2500 PICKUP 04 Electronic Control Module; (LH front under battery), gasoline, 6.0L, ID 12602802
YUKON XL 2500 03 Electronic Control Module; (LH front under battery), 6.0L
Frequently Asked Questions
Frequently Asked Questions
What is the difference between a PCM and an ECM?
ECM stands for Engine Control Module, while PCM is Powertrain Control Module. In modern vehicles like your Sierra, the PCM typically controls both the engine and the transmission, integrating the functions into one unit. For this application, the terms are often used interchangeably.
How do I provide my VIN for programming?
After you complete your purchase, simply reply to your order confirmation email with your 17-digit VIN. You can also send it to us through our website’s contact form with your order number. We cannot ship your part until we receive your VIN.
Will I need to do anything after installation?
Yes. After installing the new PCM, you must perform a security relearn procedure. This syncs the module to your vehicle’s anti-theft system and keys. It’s a simple procedure that takes about 30 minutes and does not require any special tools. Instructions are widely available online or in your vehicle’s service manual.
Is this a plug-and-play part?
Because it comes programmed to your VIN, it is as close to plug-and-play as you can get. The only additional step is the security relearn procedure, which is required for the vehicle to start and run. No dealer visit is necessary.
Why is matching the service number important?
The service number on your original PCM corresponds to a specific hardware and software configuration used by GM. While our programming can account for many variations, matching the service number (or using a compatible one from our list) ensures the hardware inside the module is 100% correct for your truck’s features.