If your 1998-1999 GMC Savana 3500 Van is giving you headaches with unpredictable stalling, a persistent check engine light, or a frustrating no-start condition, you’ve likely pinpointed the culprit: a failing Powertrain Control Module (PCM). As the electronic brain of your vehicle, when the PCM falters, everything from fuel delivery to transmission shifting can become erratic. This isn’t just an inconvenience; for a workhorse like the Savana, it means downtime and lost productivity.
This is your direct, reliable solution. We offer a genuine, used OEM PCM that is meticulously programmed to your van’s specific Vehicle Identification Number (VIN). This isn’t a generic, off-the-shelf part. Before we ship it, we flash it with the latest official GM software updates. This process ensures that known bugs and drivability issues from the factory are corrected, giving you performance and reliability that’s often better than the original. Getting your hands on a quality 1998-1999 Savana 3500 PCM is the critical first step to getting your vehicle back in service.
A Technician’s Notebook
I remember a customer with a ’99 Express 3500—same platform as the Savana—that had a ghost of a problem. It would randomly stall at idle, but never threw a consistent code. We checked fuel pressure, sensors, everything. Finally, we hooked up a scope to the PCM’s main processor. We saw intermittent voltage drops inside the module itself. The internal circuits were failing under heat soak. We swapped in a VIN-programmed PCM like this one, and the problem vanished instantly. These older PCMs are notorious for failing this way; it’s a repair I’ve done hundreds of times.
Common Signs of a Failing GM PCM
A failing computer can mimic many other problems. If you’re a professional technician or a seasoned DIYer, you’ll recognize these classic symptoms of a bad PCM in this generation of GM trucks and vans.
- ✔ Your vehicle fails to start or starts intermittently.
- ✔ The check engine light is on with codes like P0601 (Internal Memory Error) or P0606 (PCM Processor Fault).
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ The engine runs rough, stalls, or misfires.
- ✔ Loss of communication with the diagnostic scan tool.
A Straightforward Guide to Installation
One of the biggest advantages of this 1998-1999 Savana 3500 PCM is that it arrives ready for installation. Since we handle the programming, you don’t need a trip to the dealership or expensive scan tools for flashing. Just follow these simple steps.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most Savana and Express vans, the PCM is located in the engine compartment on the driver’s side, near the firewall or air filter housing.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Plug the wiring harness connectors firmly into the new module. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In some cases, a simple security relearn procedure is needed. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for the exact steps.
Verified Vehicle Compatibility
This module, identified by service ID 9355699, is a direct replacement for part numbers 16258815, 09355699, 16266645, 16250279, and 09366810. It is guaranteed to fit the following gasoline-engine GM vehicles:
- ✔ 1998-1999 Chevrolet & GMC C/K 1500, 2500, 3500 Pickups
- ✔ 1998-1999 Chevrolet Suburban 1500 & 2500
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500, 2500, 3500 Vans
- ✔ 1999 Cadillac Escalade
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Chevrolet S10, GMC Sonoma, Isuzu Hombre (4.3L)
- ✔ 1998 Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada, GMC Envoy (4.3L)
This reliable, programmed 1998-1999 Savana 3500 PCM is the most efficient way to solve complex electronic issues and restore your vehicle’s core functionality.
Frequently Asked Questions
Do I need to get this computer programmed by a dealer?
No. This PCM comes fully programmed to your vehicle’s VIN with the latest GM software before it is shipped. It is ready to be installed upon arrival.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This provides a reliable and cost-effective solution compared to sourcing a new, often unavailable, module.
What information do you need from me?
After you complete your purchase, you will need to provide us with your vehicle’s 17-digit VIN. We cannot program or ship the module without it.
Will this fix my specific problem?
This part corrects issues directly caused by a faulty PCM. While it resolves the most common symptoms like no-start, stalling, and internal error codes, you should always ensure your vehicle has been properly diagnosed by a qualified technician.
What does ‘VIN-programmed’ actually mean?
It means we load the specific software and calibrations from GM that match your vehicle’s factory options, engine, transmission, and emissions equipment. This ensures seamless integration and proper function, just like the original module.