Is Your GM Truck or Van Running Rough?
If your 1998-1999 GMC Savana, Chevrolet Express, or C/K pickup is experiencing perplexing engine issues, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer, the PCM manages everything from fuel injection and ignition timing to transmission shifting and emissions control. When it starts to fail, it can cause a cascade of problems that are difficult to diagnose, leaving you stranded and frustrated. This replacement PCM, part number 09355699, is the definitive solution to restore your vehicle’s performance, reliability, and drivability.
This isn’t just a used part pulled from a shelf. We provide a crucial service: we flash the module with the latest official GM software updates specifically for your vehicle. By providing your Vehicle Identification Number (VIN) during checkout, you receive a PCM that is precisely calibrated to your vehicle’s original specifications, ensuring seamless integration and optimal operation right out of the box. This eliminates the need for expensive trips to the dealership for programming.
From the Diagnostic Bay
I once had a ’99 Suburban in the shop with the most frustrating intermittent stall. It would run perfectly for days, then die at a stoplight without warning. No codes, no check engine light. We checked fuel pressure, ignition components, and sensors—everything tested fine. The customer was ready to give up on the truck. On a hunch, we connected a scope to the PCM’s main power and ground circuits and monitored it during a long test drive. Just before it stalled, we saw a voltage drop inside the module itself. The internal board had a micro-fracture that only opened up at certain temperatures. We installed a VIN-programmed PCM just like this one, and the truck has been running flawlessly for the owner ever since. Sometimes, the brain is the last place you look, but it’s the root of the problem.
Symptoms of a Failing PCM
A faulty PCM can manifest in various ways. If you’re noticing any of the following issues, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Check Engine Light is on with communication-related error codes (e.g., U-codes).
- ✔ Engine cranks but refuses to start.
- ✔ Intermittent stalling or shutting off while driving.
- ✔ Rough or erratic idling.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Inconsistent or non-functional gauges on the instrument cluster.
- ✔ The vehicle fails to pass an emissions test.
Why Choose a VIN-Programmed 1998-1999 Savana PCM?
This module is the heart of your vehicle’s engine management system. Our process ensures you get a reliable and correctly configured part. Sourced from salvaged vehicles, each unit is carefully inspected before being programmed. Using your VIN, we access the GM database to load the exact software your truck or van was built with, including any subsequent updates for improved performance and reliability. This tailored approach makes installation straightforward. In most cases, after installation, you will only need to perform a simple security relearn procedure (often called the Passlock relearn), which can be done in your driveway without special tools. This 1998-1999 Savana PCM is a cost-effective and dependable way to get your vehicle back on the road.
Broad Compatibility Across the GM Lineup
This versatile module, identified by service number 09355699 (and interchangeable with 16266645, 9355699, 16250279, 16258815, 09366810, 9366810), was used in a wide array of GM’s most popular trucks, vans, and SUVs from the late 90s. This includes the Chevrolet C/K 1500, 2500, and 3500 pickups, Suburban, Tahoe, Express vans, and their GMC counterparts like the Sierra, Yukon, and Savana. It also fits models like the Cadillac Escalade, Oldsmobile Bravada, and Chevrolet S10/Blazer. Please verify the part number on your original module and consult the detailed fitment list to confirm compatibility.
Frequently Asked Questions
What is the difference between a PCM, ECM, and ECU?
These terms are often used interchangeably. PCM (Powertrain Control Module) is the most accurate for this part, as it controls both the engine and transmission. ECM (Engine Control Module) typically controls only the engine. ECU (Electronic Control Unit) is a more generic term for any vehicle computer. For this generation of GM vehicles, it’s a PCM.
Do I need to do anything after installing this module?
Yes. Because the module is programmed to your VIN, it will be ready to work with your engine and transmission. However, you will likely need to perform a security relearn procedure so it communicates with your vehicle’s anti-theft system. This procedure typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Instructions are readily available online for your specific model.
Where do I find my VIN?
Your 17-digit VIN can be found on a metal plate on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Is this a new part?
No, this is a high-quality, tested used part sourced from a salvaged vehicle. Each unit is inspected to ensure it is fully functional before being programmed and shipped.
Why does this part fit so many different vehicles?
General Motors used this hardware across a wide range of trucks and vans with similar engine families (like the 4.3L V6, 5.0L V8, and 5.7L V8). The specific software, which we program using your VIN, is what tailors its operation to your exact make, model, and options.
What happens if I don’t provide my VIN?
We cannot ship the module without your VIN. The programming is essential for the part to function correctly in your vehicle. The order will be held until the VIN is provided to ensure you receive a part that works.