Is Your GM Truck or Van Acting Up? The PCM is Often the Culprit.
If your 1998 Chevrolet S10, GMC Sonoma, or another GM vehicle from that era is suddenly giving you headachesโlike refusing to start, shifting erratically, or displaying a persistent Check Engine Lightโthe Powertrain Control Module (PCM) is a primary suspect. Over my 20+ years in the shop, I’ve seen countless of these units fail, often leading to expensive misdiagnoses. The symptoms can be confusing, but the solution is straightforward.
This is a reliable, used OEM Powertrain Control Module, part number 16266645, that has been meticulously tested and is ready for a new life in your vehicle. The most critical service we provide is programming it specifically to your vehicle’s 17-digit Vehicle Identification Number (VIN) before it ships. This isn’t just a convenience; it’s essential for proper function. The VIN tells the computer everything it needs to know about your truck’s specific configurationโengine size, transmission type, gear ratios, and factory options. Without this step, you’re just plugging in a guess.
Why Choose Our Programmed 1998 S10 Sonoma PCM?
When you order from us, you’re not just getting a part; you’re getting a complete, ready-to-install solution backed by hands-on expertise. We bridge the gap between a complex electronic component and a simple, effective repair.
- โ VIN-Programmed for You: We load the latest GM-certified software for your exact vehicle. This ensures seamless communication and performance.
- โ No Additional Programming Needed: Forget expensive trips to the dealership. This module is truly plug-and-play.
- โ Solves Common Issues: An effective fix for no-start conditions, poor fuel economy, harsh shifting, and various diagnostic trouble codes (DTCs).
- โ Broad Compatibility: This single unit is a direct replacement for multiple part numbers, making it a versatile solution for a wide range of GM trucks and vans.
Expert Pro Tip: Check Your Connectors!
Before you condemn your old PCM, take a moment to inspect the electrical connectors that plug into it. On these late-90s GM trucks, the PCM is often located in the engine bay where it’s exposed to the elements. I’ve seen dozens of cases where corrosionโthat green, crusty buildupโon the connector pins was the real cause of the problem. A simple cleaning with a small wire brush and some electrical contact cleaner can sometimes restore the connection. If your pins are clean and the problems persist, then it’s time to replace the module itself.
Plug-and-Play Installation: Get Back on the Road Fast
Installing your new PCM is a job most DIYers can handle in under 30 minutes with basic hand tools. Just follow these simple steps:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998 S10/Sonoma models, the PCM is located in the engine compartment, often near the battery or on the fender wall. It’s a black box with several large electrical connectors.
- Disconnect the Old Unit: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the old PCM from its mounting bracket.
- Install the New PCM: Bolt your new, pre-programmed PCM into place. Firmly reconnect the wiring harnesses, ensuring the locking tabs click securely.
- Reconnect the Battery: Re-attach the negative battery terminal. Your vehicle is now ready to start with its new brain.
Guaranteed Compatibility
This module is a direct replacement for the following part numbers: 09355699, 16266645, 16250279, 16258815, and 09366810. It is guaranteed to fit and function in the vehicles listed below that require service ID 9355699. Please provide your VIN upon purchase to ensure we send you a perfectly matched and programmed unit.