Is Your 2003 Blazer or Jimmy Running Rough?
There’s nothing more frustrating than a truck you can’t rely on. If your 2003 Chevy Blazer S10 or GMC Jimmy S15 is suddenly stalling, shifting erratically, or showing a persistent Check Engine Light that no other repair seems to fix, the problem often points directly to a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, its health is critical for performance, fuel economy, and reliability. When it starts to fail, it can create a cascade of confusing and intermittent issues that are difficult to diagnose.
The Direct Solution: A VIN-Programmed PCM
Forget expensive dealership visits and the uncertainty of a junkyard part. This Powertrain Control Module is the straightforward, reliable solution you need. We take the guesswork out of the repair by pre-programming the module specifically for your vehicle using your VIN. This ensures it has the latest GM software updates and communicates perfectly with your truck’s specific options and systems right out of the box. It’s a true plug-and-play fix designed to get you back on the road quickly and confidently.
Expert Pro Tip: Check Your Harness First
In my 20+ years as a technician, I’ve seen many S-series trucks like the Blazer and Jimmy come in with PCM-related codes. Before you condemn the module, take a close look at the wiring harness where it runs near the PCM in the right front of the engine compartment. The plastic loom can become brittle over time, and the wires can chafe against the fender well or brackets. A simple visual inspection and a wiggle test of the harness can sometimes reveal a short that mimics PCM failure, saving you time and money.
Common Symptoms of a Failing 2003 Blazer S10 PCM:
- โ Unexplained Check Engine Light (CEL)
- โ Engine stalling or cutting out while driving
- โ Harsh or erratic automatic transmission shifting
- โ Complete no-start condition where the engine cranks but won’t fire
- โ Noticeable decrease in fuel mileage
- โ Communication errors with diagnostic scan tools
- โ False sensor codes that return even after replacing the sensor
Simple Installation, No Dealer Required
You can perform this replacement yourself with basic hand tools, saving hundreds on labor costs. Our VIN programming service means you won’t need a trip to the dealer for expensive calibration.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the Module: On your 2003 Blazer or Jimmy, the PCM is located in the right-front of the engine compartment, near the battery.
- Disconnect Connectors: Carefully unclip and remove the electrical connectors from the old PCM. Inspect them for any corrosion or damage.
- Swap the Modules: Unbolt the old module and install the new one in its place.
- Reconnect: Securely plug the electrical connectors into your new PCM and reconnect the negative battery terminal.
- Final Check: Start the vehicle and let it idle for a few minutes to allow the systems to sync. Your truck is ready to drive!
Guaranteed Compatibility
This module is a direct replacement for a wide range of GM vehicles and is guaranteed to work if your original part carries any of the following service numbers. Please provide your VIN upon purchase to ensure perfect programming.
Compatible Service Numbers: 12581565, IS 8125815650, 12570557, 12570558, 12576106, 12576869, 12578127, 8125781270, 88864822, 89017733