Restore Your Van’s Brain and Get Back to Work
Is your 1998 or 1999 GMC Savana 1500 giving you headaches? Unexplained stalling, a persistent check engine light, or rough, unpredictable engine performance can bring your work or travels to a grinding halt. As a technician with over two decades of experience, I’ve seen countless vehicles sidelined by a faulty Powertrain Control Module (PCM). This isn’t just a part; it’s the central computer managing everything from fuel mixture and ignition timing to transmission shifting. When it fails, the symptoms can be frustratingly vague and difficult to diagnose.
This isn’t a generic, off-the-shelf computer. This is a dependable, used OEM PCM that we flash-program specifically for your vehicle using your VIN. We install the latest GM software updates, ensuring optimal performance and communication with your van’s other modules. By providing your VIN at checkout, you receive a part that is truly plug-and-play, eliminating the need for an expensive trip to the dealership for programming. This is the most direct and cost-effective solution to get your reliable GM van back on the road.
Case Study: A Tricky Diagnosis
A few months back, a 1999 Savana 2500 work van came into my shop. The owner, a local plumber, was at his wit’s end. The van would randomly refuse to start, but only after it was hot. No check engine light, no clear codes. He’d already replaced the battery and starter. After checking fuel pressure and spark, which were intermittent, my gut told me to look at the PCM. On these vans, heat soak from the engine compartment can slowly bake the internal components of the module over 20+ years. We swapped in a VIN-programmed PCM just like this one, and the problem vanished instantly. It’s a classic failure I’ve seen dozens of times, and a simple replacement is often the definitive fix.
Is Your Van Showing These Symptoms?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, a faulty module is a likely culprit:
- ✔ Check Engine Light is on with communication error codes (like P0601, P0605) or fuel/air metering codes.
- ✔ The engine cranks but refuses to start.
- ✔ Rough or inconsistent idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ The transmission shifts harshly or at the wrong times.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Replacing the PCM on your Savana is a job most DIYers can handle in under an hour with basic hand tools. Our pre-programming service saves you the most complicated step.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On the 1998-1999 Savana/Express vans, the PCM is typically located in the engine compartment, on the driver’s side, often near the battery or firewall.
- Disconnect the Module: Carefully unplug the electrical connectors. These GM connectors have locking tabs that need to be released before you can pull them free. Never force them.
- Remove the Old Unit: Unbolt the PCM from its mounting bracket. Keep the hardware, as you’ll need it for the new module.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Plug the electrical connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Security Relearn (If Needed): In most cases, you can simply start the vehicle. However, some GM vehicles may require a simple security relearn procedure. Turn the key to the ‘ON’ position for 10-15 minutes, then turn it off, and then start the engine.
Verified Vehicle Compatibility
This module, identified by part number 16266645 or service ID 9355699, is a direct replacement for a wide range of GM trucks and vans. Please verify your original part number to ensure a perfect match. This unit fits the following vehicles:
- ✔ 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500/2500/3500 Vans (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban 1500/2500 (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- ✔ 1999 Cadillac Escalade
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Chevrolet S10, GMC Sonoma, Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada, Isuzu Hombre (4.3L V6 models)
- ✔ 1998 Oldsmobile Bravada & GMC Envoy
Note: This part is a direct replacement for multiple part numbers, including 09355699, 16250279, 16258815, and 09366810.
Frequently Asked Questions
Do I need to get this computer programmed by a dealer?
No. We flash the computer with the latest GM software and program it to your vehicle’s specific VIN before we ship it. It arrives ready for installation.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This provides OEM reliability at a fraction of the cost of a new unit.
How do I know if this is the right part for my van?
The best way is to match the part number from your original PCM. This unit replaces several numbers, including 16266645 and 09355699. If you’re unsure, send us a message with your VIN and we can verify compatibility.
What tools do I need for installation?
You’ll typically only need a basic socket set (e.g., 10mm socket) to remove the mounting bolts and a flat-head screwdriver to help gently release the connector tabs. No special electronic tools are required.