Is Your GM Truck or Van Running Rough?
If you’re dealing with a persistent Check Engine Light, erratic engine performance, harsh transmission shifting, or even a no-start condition in your 2005 Blazer S10 or Jimmy S15, a failing Powertrain Control Module (PCM) is often the culprit. As the brain of your vehicle, when the PCM starts to fail, it can cause a cascade of frustrating and hard-to-diagnose problems. I’ve seen it countless times in my shop: a vehicle comes in with a list of seemingly unrelated issues, and after hours of chasing wires and swapping sensors, the root cause points directly back to the main computer.
From the Shop Floor: A Real-World Scenario
“A customer’s 2005 GMC Savana van came in last week with these exact symptoms: a random cylinder misfire code (P0300) that wouldn’t go away and a transmission that slammed into gear. The owner had already replaced plugs, wires, and the transmission fluid. After connecting my scan tool, I noticed the injector pulse width data was erratic on two cylinders. This is a classic sign of failing injector driver circuits inside the PCM. We installed one of our pre-programmed modules, and the van ran perfectly, shifting smoothly with no more codes. It saved the customer from needlessly replacing more parts.”
The Direct Solution: A VIN-Programmed 2005 Blazer S10 PCM
This isn’t just a replacement part; it’s a complete solution. We take a thoroughly tested and reliable PCM, service number 12602801, and program it specifically to your vehicle’s Vehicle Identification Number (VIN). This process ensures 100% compatibility by loading the latest, most stable software updates directly from GM. This corrects factory bugs and optimizes performance for a seamless installation.
Symptoms of a Failing PCM:
- โ Persistent Check Engine Light (CEL) with various codes
- โ Poor fuel economy
- โ Engine stalling, stumbling, or misfiring
- โ Harsh or erratic automatic transmission shifting
- โ Vehicle won’t start, but the battery and starter are good
- โ Communication errors with scan tools (U-codes)
- โ Loss of power and sluggish acceleration
Plug-and-Play Installation: No Dealer Visit Required
Replacing your PCM is a straightforward job you can do in your own driveway. By sending us your VIN, we handle all the complex programming, so you receive a module that’s ready to install right out of the box. A security relearn procedure may be required, which takes about 30 minutes and involves only your ignition key.
- Safety First: Disconnect the negative battery terminal and wait 10 minutes for the system to discharge.
- Locate the PCM: On a 2005 Blazer S10/Jimmy S15, it’s typically found in the right-hand front of the engine compartment. For other compatible vehicles like Silverado or Express vans, it’s often under the battery tray or on the driver’s side of the engine bay.
- Disconnect Connectors: Carefully unlatch and remove the wiring harness connectors from the old module.
- Swap the Modules: Unbolt the old PCM and secure the new one in its place.
- Reconnect Everything: Firmly plug the wiring harnesses into your new module and reconnect the negative battery terminal.
- Perform Security Relearn: Turn the key to the ‘ON’ position for 10-12 minutes, then ‘OFF’ for 30 seconds. Repeat this cycle three times. On the final cycle, the vehicle should start.
This module is a direct replacement for part numbers 12589462, 12602801, and 89017749 and fits a wide range of GM vehicles. Please verify your part number and use our fitment chart to confirm compatibility. By providing your VIN upon purchase, you guarantee a perfectly matched computer for your truck or van, restoring its original performance and reliability.