Is Your 2004 Chevy S10 or GMC Sonoma Running Rough?
If you’re dealing with a persistent check engine light, erratic engine behavior, stalling, or a no-start condition, the culprit is often a failing Powertrain Control Module (PCM). As the central computer of your truck, the PCM is responsible for managing everything from fuel injection and spark timing to transmission shifting and emissions control. When it starts to fail, it can cause a cascade of frustrating and difficult-to-diagnose problems. This replacement PCM, part number 89017739, is the definitive solution to restore your vehicle’s performance, reliability, and efficiency.
From the Diagnostic Bay
We had a 2004 GMC Sonoma come into the shop that was driving the owner crazy. It would randomly stall at stoplights and had a check engine light with a handful of seemingly unrelated communication codes. The owner had already replaced the crank sensor and a few other parts with no luck. After hooking up our professional scan tool, we noticed the data stream from the PCM would drop out intermittently. This pointed directly to an internal failure in the module. We installed one of our VIN-programmed PCMs, performed the security relearn, and the truck ran perfectly. It’s a classic case where chasing individual codes can be misleading, and the root cause is the main computer itself.
Common Symptoms of a Failing 2004 S10 PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns immediately.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Rough idling or inconsistent engine RPMs.
- ✔ A complete no-start condition where the engine cranks but won’t fire up.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication error codes (U-codes) stored in the system.
- ✔ Failure to pass state emissions testing.
The Importance of VIN Programming
This isn’t just a generic, off-the-shelf part. To ensure perfect compatibility and function, we program this PCM specifically to your vehicle’s 17-digit Vehicle Identification Number (VIN) before it ships. This critical step loads all the correct software and calibrations for your S10’s specific engine, transmission, and options. It also ensures seamless communication with other modules in your vehicle, like the anti-theft system (Passlock/VATS). Simply provide your VIN after purchase, and we’ll handle the rest, shipping you a module that’s ready for installation.
Installation and Setup
On the 2004 S10, S15, and Sonoma, the PCM is typically located in the engine compartment on the right-hand (passenger) side. Installation is straightforward for a DIY mechanic or any professional technician.
- Disconnect the Battery: Always disconnect the negative battery terminal before working on any electronic components.
- Locate and Remove the Old PCM: Unplug the electrical connectors and unbolt the module from its bracket.
- Install the New PCM: Bolt the new module in place and securely reconnect the wiring harnesses.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn: In most cases, you will need to perform a security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This procedure can typically be done without special tools and involves a sequence of key turns. Instructions are widely available online or in service manuals.
This module is a direct replacement for part numbers 89017739 and 12586243 and fits a wide range of 2004 GM vehicles, including the Chevy Silverado, GMC Sierra, Corvette, Trailblazer, Express/Savana vans, and more. Verify your part number or contact us to ensure compatibility.
Frequently Asked Questions
Why does this PCM need my vehicle’s VIN?
Your VIN allows us to load the exact GM-specified software and calibrations for your truck’s engine, transmission, and factory options. This ensures optimal performance, fuel economy, and proper function of all systems, including the anti-theft system.
Is this part difficult to install?
The physical installation is straightforward, involving unplugging connectors and removing a few bolts. The most important step is performing the security relearn procedure after installation, which allows your vehicle’s keys to be recognized by the new PCM.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this will resolve the issue. It’s crucial to have your vehicle properly diagnosed to confirm the PCM is the root cause of the problem before ordering.
Where is the PCM located on my 2004 S10?
On the 2004 Chevy S10 and GMC Sonoma, the PCM is located in the engine bay, typically on the right-hand (passenger side) front area.
What if my original part number is 12586243?
This module is a fully compatible replacement for both 89017739 and 12586243. We will program it to function identically to your original unit based on your VIN.