Is Your GM Truck or Van Running Rough?
If your 2005-2007 GMC Sierra 2500, Chevrolet Silverado, or other compatible GM vehicle is experiencing baffling issues like stalling, erratic shifting, a persistent check engine light, or a complete no-start condition, the culprit is often a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can wreak havoc on your vehicle’s performance, fuel economy, and reliability. Don’t let a bad module keep you off the road. This is your direct, plug-and-play solution.
This listing is for a genuine GM Powertrain Control Module, part number 89017749, which is also a direct replacement for part numbers 12589462 and 12602801. The critical difference with our service is that we professionally program the module to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This ensures that the unit has the latest GM software updates and is perfectly matched to your vehicle’s factory options, engine, and transmission. This eliminates the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
We had a 2006 Silverado 2500 with the 8.1L come in that was driving the owner crazy. It would randomly stall at stoplights, but only when warm. It threw a dozen different codes—O2 sensor, misfire, communication loss—and the owner had already replaced a handful of sensors. We ran full diagnostics and everything seemed to check out intermittently. On a hunch, we monitored the PCM’s data stream and noticed the processor would occasionally drop out. We swapped in one of our pre-programmed modules, performed the security relearn, and the truck ran perfectly. It’s a classic case of a failing computer causing phantom problems that look like something else entirely.
Diagnosing and Replacing Your 2005-2007 Sierra PCM
The PCM is the brain of your vehicle’s powertrain. It takes information from sensors all over the engine and transmission to control fuel injection, spark timing, emissions equipment, and transmission shift points. When it begins to fail, the symptoms can be varied and confusing. A replacement is often the only way to restore proper function and get your truck back to factory-spec performance.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light (CEL) is illuminated, often with U-series (communication) codes.
- ✔ Engine misfires, runs rough, or stalls unexpectedly.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Vehicle will crank but refuses to start.
- ✔ Intermittent issues that disappear and reappear without a clear cause.
- ✔ Failure to pass state emissions testing.
Simple Installation Process
Once you receive your pre-programmed module, installation is straightforward. On most trucks like the Sierra and Silverado, the PCM is located in the engine bay on the driver’s side, under or near the battery. Simply disconnect the battery, unplug the electrical connectors from the old PCM, unbolt it from its bracket, and install the new one in its place. After reconnecting everything, you will likely need to perform a simple security relearn procedure (often called a CASE relearn or Passlock relearn) to sync the new module with your vehicle’s anti-theft system. This can typically be done without any special tools and we can provide instructions for the process.
Frequently Asked Questions
Do I need to program this module?
No. This module comes fully programmed to your vehicle’s VIN. Simply provide us with your VIN after purchase, and we will flash the unit with the latest GM software before shipping it to you.
Where is the PCM located on my 2006 Sierra 2500?
On most 2005-2007 classic body style Sierra and Silverado trucks, the PCM is located in the engine compartment on the driver’s side, typically under the battery tray or mounted near the fender.
What is the security relearn procedure?
It’s a simple procedure to sync the new PCM to your vehicle’s anti-theft system. It usually involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. This allows the components to communicate and authorize the new module.
Will this fit my vehicle if my part number is 12589462?
Yes. This module, 89017749, is a direct, updated replacement for older part numbers including 12589462 and 12602801.
What information do you need from me after I order?
We only need your 17-digit Vehicle Identification Number (VIN). You can find this on your vehicle’s registration, insurance card, or on the driver’s side dashboard viewable through the windshield.
Will this fix my check engine light?
If the check engine light and associated running issues are caused by a faulty PCM, this part will resolve the problem. It is essential to ensure proper diagnosis has been performed, as other failing sensors or components can cause similar symptoms.