Get Your GM Van or Truck Running Right Again
Is your 1998-1999 GMC Savana 1500 van giving you headaches? If you’re dealing with frustrating issues like a no-start condition, rough idling, erratic shifting, or a persistent Check Engine Light, the problem often points directly to a failing Powertrain Control Module (PCM). As the central computer of your vehicle, a faulty PCM can cause a wide range of problems that are impossible to fix by just replacing sensors. This is a common failure point I’ve seen countless times over my 20+ years in the shop, but the solution is more straightforward than you might think.
This is a reliable, tested, and pre-programmed PCM, part number 9355699, sourced from a salvaged vehicle. The biggest advantage we offer is our professional programming service. Before we ship it, we flash the module with the latest GM software updates and program it specifically to your vehicle’s VIN. This means it arrives at your door ready for installation, saving you a costly and time-consuming trip to the dealership. You get a dependable part that restores original performance without the hassle.
From the Diagnostic Bay: The Case of the Intermittent Work Van
I remember a 1999 Savana 2500 work van that came into my shop a few years back. The owner was at his wit’s end. The van would run perfectly for days, then suddenly stall at a stoplight and refuse to restart for an hour. He had already replaced the fuel pump and ignition coil pack, but the problem persisted. When I connected my scan tool, I found no active trouble codes, but in the history data, I saw a few U-series communication loss codes. This is a classic sign that the PCM itself is failing intermittently. The internal processors overheat or the solder joints crack, causing it to randomly shut down. We swapped in a pre-programmed 1998-1999 Savana 1500 PCM, performed the security relearn, and the van never had the issue again. It’s a textbook example of how a failing computer can mimic other component failures.
Is Your GM Vehicle Showing These Red Flags?
A failing PCM doesn’t always die suddenly. It often gives warning signs. If you’re experiencing any of the following, your PCM is the likely culprit:
- ✔ Check Engine Light is on with codes for internal module failure (like P0601, P0605, P0606).
- ✔ Vehicle refuses to start or stalls intermittently for no apparent reason.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Engine performance issues like misfiring, stumbling, or hesitation.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Your PCM Swap
Replacing the PCM on these GM vehicles is a job most DIYers can handle in under an hour with basic hand tools. This pre-programmed module makes it even simpler. While specific steps may vary slightly by model, here is a general guide:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent electrical shorts.
- Locate the PCM: On most Savana/Express vans, the PCM is located in the engine compartment on the driver’s side, near the battery or firewall. On trucks and SUVs, it’s typically on the driver’s side fender.
- Disconnect the Connectors: Carefully unclip and remove the electrical wiring harness connectors. These connectors have locking tabs that need to be released before you can pull them off. Avoid forcing them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are usually two or three bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed 1998-1999 Savana 1500 PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Firmly plug the wiring harness connectors back into the correct sockets on the new PCM. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In most cases, you will need to perform a simple security relearn procedure, also known as the CASE relearn. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times. This allows the new PCM to synchronize with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This module, identified by service number 9355699, is a direct replacement for a wide range of GM trucks, vans, and SUVs. Please match your original part number or use the compatibility list below to ensure a perfect fit. This unit interchanges with part numbers: 09355699, 16266645, 16250279, 16258815, 09366810, and 9366810.
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
EXPRESS 1500/2500/3500 VAN 98-99
GMC 1500 PICKUP 98-99 (5.0L, 5.7L)
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
SAVANA 1500/2500/3500 VAN 98-99
CADILLAC ESCALADE 99
CHEVROLET SUBURBAN 1500/2500 98-99 (Gasoline)
CHEVROLET TAHOE 98-99 (Gasoline)
GMC YUKON 98-99
ASTRO / SAFARI (GMC) 98
BLAZER S10 / JIMMY S15 98 (w/o build date opt ZN4)
BRAVADA 98 (w/o build date opt ZN4)
ENVOY 98 (w/o build date opt ZN4)
ISUZU HOMBRE 98 (4.3L, w/o extended build date opt ZN4)
S10/S15/SONOMA 98 (4.3L, w/o build date opt ZN4)
Frequently Asked Questions
Why do I need to provide my VIN?
Your Vehicle Identification Number (VIN) is essential for us to program the computer correctly. It contains specific information about your vehicle’s engine, transmission, and factory options. This ensures the 1998-1999 Savana 1500 PCM works perfectly once installed.
Is this a brand new part?
No, this is a high-quality, tested used part that has been carefully removed from a salvaged vehicle. We inspect and verify each unit to ensure it’s fully functional before programming and shipping.
Will I need to do anything after installation?
After installing the PCM and reconnecting the battery, you will need to perform the vehicle’s security relearn procedure. This is a simple process that takes about 30 minutes and requires no special tools. It allows the module to sync with your vehicle’s anti-theft system.
What if my part number doesn’t match exactly?
This module (9355699) replaces several other part numbers, including 16266645, 16250279, and others listed in the description. As long as your vehicle is on the compatibility list, this programmed module will function correctly.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine and transmission functions. Erratic shifting, slipping between gears, or failure to shift are common symptoms of a failing PCM. Replacing it often resolves these issues.