Restore Your Vehicle’s Brain and Get Back on the Road
Is your 2005 GMC Safari or another compatible GM vehicle giving you headaches? If you’re dealing with a persistent Check Engine Light, unpredictable stalling, poor fuel economy, or erratic shifting, the problem often points directly to a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can create a cascade of frustrating issues. In my 20+ years of diagnostics, I’ve seen drivers replace countless sensors and parts, only to find the root cause was the PCM all along.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and high dealership costs out of the equation. When you order, simply provide your vehicle’s 17-digit VIN. Our technicians will then program this module with the very latest official GM software updates specific to your vehicle. This ensures optimal performance, fuel efficiency, and transmission function right out of the box. This is the same service a dealership provides, but without the hassle and extra expense.
Case Study: The Ghost in the Machine
A customer brought in a 2006 Savana van with an intermittent misfire that no one could solve. He’d already replaced spark plugs, wires, and the coil pack. The van would run fine for days, then suddenly start stumbling at a stoplight. After hooking up my diagnostic scanner and monitoring live data, I noticed the injector pulse width on cylinder 3 would occasionally drop out for a split second—too fast to set a specific misfire code, but enough to cause a stumble. This wasn’t a bad injector; it was the driver circuit inside the PCM failing under certain conditions. We installed a VIN-programmed PCM, and the problem was solved instantly. It’s a classic example of how a failing module can mimic other component failures.
Is Your Vehicle Showing These Signs?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Stored diagnostic trouble codes (DTCs) such as P0601, P0602, or P0606
- ✔ The engine cranks but refuses to start
- ✔ Unexplained drop in fuel economy
- ✔ Harsh, delayed, or incorrect transmission shifting
- ✔ Noticeable loss of power or engine hesitation
- ✔ Rough or unstable idling
A Straightforward Guide to Installation
This PCM is designed for a direct-fit replacement. While professional installation is always an option, a confident DIYer can complete the job. After installation, a simple security relearn procedure is required, which does not need a special scan tool.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: On most listed vehicles, the PCM is located in the engine compartment, often near the battery or firewall. For the 2005 Safari, it’s on the driver’s side front, by the battery.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that must be released. Then, unbolt the module from its mounting bracket.
- Install the New Module: Seat the new PCM in the bracket, tighten the mounting bolts, and securely plug in all electrical connectors until they click.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Security Relearn (CRITICAL): Turn the key to the “ON” position (without starting the engine). Leave it on for 10-12 minutes. The “Security” light on the dash should turn off. Turn the key off for 10 seconds, and then start the vehicle. It is now ready to drive.
Will This Fit My Vehicle?
This module, part number 89017749, is a direct replacement for part numbers 12589462 and 12602801. It is guaranteed to fit the following makes and models:
- ASTRO 05 (LH front by battery)
- AVALANCHE 2500 05-06 (LH front under battery)
- BLAZER S10/JIMMY S15 05 (RH front engine compartment)
- CTS 04-05 V-Series (ID 12589462 or 12602801)
- EXPRESS/SAVANA 1500 VAN 05-07 (LH rear engine compartment)
- EXPRESS/SAVANA 2500 VAN 05-07 Gasoline (LH rear engine compartment)
- EXPRESS/SAVANA 3500 VAN 05-07 Gasoline (LH rear engine compartment)
- SAFARI (GMC) 05 (LH front by battery)
- SIERRA/SILVERADO 1500 PICKUP 05-07 Classic Style, 4.3L (LH front under battery)
- SIERRA/SILVERADO 2500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
- SIERRA/SILVERADO 3500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
- SUBURBAN 2500 05-06 8.1L (LH front under battery)
- YUKON XL 2500 05-06 8.1L (LH front under battery)
Frequently Asked Questions
What information do you need to program the module?
We only need your 17-digit Vehicle Identification Number (VIN). You can typically find this on your vehicle’s registration, insurance card, or on the driver’s side dashboard viewable through the windshield.
Do I need to send my old PCM back?
No, there is no core charge for this module. You can keep your old part.
Is this part difficult to install myself?
The physical replacement is straightforward for anyone comfortable with basic hand tools. The most important step is performing the security relearn procedure correctly, as detailed in our installation guide. It’s simple and requires no special equipment.
My original part number is 12589462. Will this work?
Yes. This module, 89017749, is a fully compatible and updated replacement for part numbers 12589462 and 12602801. It will function identically once programmed to your VIN.
What if I have questions during installation?
Our team of experienced technicians is here to help. We provide support to ensure you can get your vehicle back on the road. Your success is our priority.