Get Your Workhorse Van Back in Service Fast
If your 1998-1999 GMC Savana 3500 is giving you headaches with no-start conditions, erratic shifting, or a persistent Check Engine Light, the Powertrain Control Module (PCM) is a likely culprit. As the brain of your vehicle’s engine and transmission, a failing PCM can bring your work to a grinding halt. This isn’t just an inconvenience; it’s lost time and money. I’ve spent two decades under the hood of vehicles just like yours, and I know that getting a reliable, correctly programmed replacement is critical.
This is a dependable, tested OEM PCM that we program specifically to your van’s Vehicle Identification Number (VIN). Forget the expensive dealership visit and the hassle of coordinating programming. We flash this module with the latest GM software updates before it even leaves our facility. This ensures it communicates perfectly with your vehicle’s systems, restoring the performance and reliability you depend on. This is the most direct and cost-effective solution to get your 1998-1999 Savana 3500 PCM issues resolved.
A Technician’s Notebook: The Intermittent No-Start
A local contractor brought in his ’99 Savana 3500 work van. The complaint was a frustrating one: sometimes it would start perfectly, other times it would just crank and crank. He’d already replaced the battery and checked the fuel pump. After hooking up my scan tool, I noticed communication with the PCM was dropping out intermittently. On these older GM platforms, heat soak and vibration can cause microscopic cracks in the PCM’s internal solder joints. We swapped in a VIN-programmed module, and the van fired up consistently, hot or cold. It wasn’t a fuel or spark part issue; it was the computer failing to command them. This simple swap saved him from chasing phantom problems and got his business moving again.
Is Your Savana Van Exhibiting These Issues?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty PCM could be the cause:
- ✔ Unexplained Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ Vehicle refuses to start or has intermittent starting problems.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Poor fuel economy and engine performance, including stalling or rough idling.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Other modules, like the ABS, setting communication loss codes.
Straightforward Installation to Get You Running
Installing your programmed 1998-1999 Savana 3500 PCM is a manageable job for a DIYer or any professional technician. Follow these general steps to get your vehicle back on the road.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998-1999 Savana and Express vans, the PCM is located in the engine compartment, typically on the driver’s side, sometimes near the battery or on the fender wall.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released before pulling. Avoid forcing them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will 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 the wiring harnesses, ensuring they click firmly into place.
- Reconnect Battery: Reattach the negative battery terminal and tighten it.
- Perform Security Relearn (If Needed): Some GM vehicles of this era require a simple security relearn procedure. Turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle three times. On the final cycle, the vehicle should start.
Verified Compatibility for Your GM Truck or Van
This module is a direct replacement for service number 16266645 and interchanges with several other part numbers. It is compatible with a wide range of GM vehicles from 1998-1999, provided the original module has service ID 09355699. Please provide your VIN upon purchase to ensure we flash the correct software for your specific application.
CHEVROLET 2500/3500 PICKUP 98-99 (Gasoline)
EXPRESS 1500/2500/3500 VAN 98-99 (Gasoline)
GMC 1500 PICKUP 98-99 (5.0L, 5.7L)
GMC 2500/3500 PICKUP 98-99 (Gasoline)
SAVANA 1500/2500/3500 VAN 98-99 (Gasoline)
CADILLAC ESCALADE 99
CHEVROLET TAHOE 98-99 (Gasoline)
GMC YUKON 98-99
CHEVROLET SUBURBAN 1500/2500 98-99 (Gasoline)
ASTRO / SAFARI (GMC) 98
BLAZER S10 / JIMMY S15 98
S10/S15/SONOMA 98 (4.3L)
OLDSMOBILE BRAVADA 98
GMC ENVOY 98
ISUZU HOMBRE 98 (4.3L)
Frequently Asked Questions
Does this PCM really come programmed for my van?
Yes. We use the VIN you provide during checkout to flash the module with the latest official GM software for your exact vehicle configuration. This makes it a plug-and-play solution, saving you a trip to the dealer.
What is a VIN and where do I find it?
The VIN is your vehicle’s unique 17-digit identification number. You can typically find it on a plate on the driver’s side dashboard (visible through the windshield), on your vehicle’s registration, or on the driver’s side door jamb sticker.
Will I need to do a security relearn procedure after installation?
It’s highly likely. Most GM vehicles from this period with Passlock or other security systems require a simple key-cycle relearn procedure to sync the new PCM with the vehicle. The process is straightforward and described in our installation guide.
My part number is slightly different, but my vehicle is on the list. Will this work?
This module, identified by the hardware ID 09355699, serves as a replacement for multiple part numbers (including 16266645, 16250279, etc.). As long as your vehicle is on the compatibility list, our VIN-specific programming will ensure it functions correctly.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This provides an affordable and reliable alternative to finding a scarce new part, and we back it with our programming service to ensure it works for you.