Restore Peak Performance to Your GM Vehicle’s Engine
Is your truck or van plagued by a persistent Check Engine Light, rough idling, poor fuel mileage, or frustrating no-start conditions? As a technician with over two decades of experience under the hood, I’ve seen these symptoms countless times. More often than not, the root cause is a failing Powertrain Control Module (PCM)—the electronic brain of your vehicle. This isn’t just a replacement part; it’s a direct solution to restore your vehicle’s reliability and drivability.
This PCM, part number 12602801, is meticulously prepared for your specific vehicle. We take your Vehicle Identification Number (VIN) and flash the module with the very latest, most stable software directly from GM. This critical step ensures that all factory performance parameters, fuel strategies, and transmission shift points are perfectly calibrated. You’re not just fixing a problem; you’re giving your engine’s management system a fresh start with the best software available, addressing issues the original programming may have had.
From the Diagnostic Bay: The Intermittent Ghost
I once had a 2006 Savana 3500 work van in my bay that was driving the owner crazy. It would randomly refuse to start, but only after it had been driven for a while and sat for about an hour. No codes, no warning lights. He’d already replaced the battery, starter, and crank sensor. After hooking up my scope, I noticed the 5-volt reference signal from the PCM would occasionally drop out during cranking when the module was hot. The internal processor was failing under heat soak. We installed one of these VIN-programmed PCMs, and the problem was solved instantly. It’s a classic failure mode that a simple code reader will never catch.
Is Your GM Vehicle Showing These Signs?
A failing PCM can cause a wide range of confusing issues. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Persistent Check Engine Light (CEL) that won’t go away.
- ✔ Stored diagnostic trouble codes (DTCs) like P0601, P0602, or P0606 (Internal Control Module Memory/Processor Fault).
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Complete no-start or intermittent starting problems.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Installation
One of the biggest benefits of this module is its simple, direct-fit installation. Because it arrives pre-programmed, you avoid a costly trip to the dealership. While some models may require a security relearn procedure (which can be done without special tools), the physical swap is straightforward.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these vehicles, the PCM is found in the engine bay. For the GMC Safari/Chevy Astro, it’s on the driver’s side near the battery. For Silverado/Sierra trucks, it’s typically under the battery tray on the driver’s side. For Express/Savana vans, it’s in the rear of the engine compartment on the driver’s side.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. Once unplugged, unbolt the old module from its mounting bracket.
- Install the New Module: Bolt the new PCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect Battery: Reattach the negative battery terminal and tighten it.
- Perform Security Relearn (If Needed): Turn the key to the ‘ON’ position (don’t start the engine) for 10-15 minutes. The security light should turn off. Turn the key off for 10 seconds, then repeat two more times. After the third cycle, the vehicle should start and run normally.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12602801, 12589462, and 89017749. It is guaranteed to fit the following GM models and engine configurations:
– ASTRO / SAFARI (2005)
– EXPRESS / SAVANA 1500 (2005-2007)
– EXPRESS / SAVANA 2500 & 3500 (2005-2007, Gasoline)
Trucks (Gasoline):
– SILVERADO / SIERRA 1500 (2005-2007 Classic, 4.3L)
– SILVERADO / SIERRA 2500 & 3500 (2005-2007 Classic, 8.1L)
SUVs (Gasoline):
– AVALANCHE 2500 (2005-2006)
– SUBURBAN 2500 (2005-2006, 8.1L)
– YUKON XL 2500 (2005-2006, 8.1L)
– BLAZER S10 / JIMMY S15 (2005)
Cars:
– CADILLAC CTS (2004-2005, V-Series) – Verify ID 12589462 or 12602801
Is this module really plug-and-play?
Is this module really plug-and-play?
Yes! Because we program it to your vehicle’s specific VIN before shipping, it arrives ready to be installed. In most cases, this eliminates the need for any additional programming with expensive scan tools. Some vehicles may require a simple key-cycle security relearn procedure, which you can do yourself in about 30 minutes.
How do I give you my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically add it as a note during checkout or reply to your order confirmation email. We cannot program and ship the module without it.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine functions and transmission shift commands. If the module is failing, it can send erratic signals to the transmission, causing harsh shifts, slipping, or delayed engagement. Replacing a faulty PCM often resolves these communication-based transmission issues.
Is this a used part?
This is a high-quality, inspected, and tested recycled OEM part. Each unit is verified to be fully functional before being programmed with the latest GM software for your VIN. This provides OEM reliability without the high cost of a brand new part from a dealer.