Restore Your Truck’s Power and Reliability
If you’re dealing with a frustrating no-start condition, a persistent check engine light, erratic shifting, or poor fuel economy in your late-90s GM truck or van, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience, I’ve seen these exact issues countless times on the shop floor. The PCM is the brain of your vehicle, and when it starts to fail, it can cause a cascade of problems that are difficult to diagnose. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded.
This is a dependable, tested, and salvaged OEM Powertrain Control Module, part number 09355699. Unlike a generic, one-size-fits-all part from a big box store, this unit is meticulously programmed to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. We flash it with the latest GM-authorized software updates, ensuring it communicates perfectly with your engine, transmission, and all related systems. This process eliminates the need for an expensive trip to the dealership for programming, making this a truly plug-and-play solution for both seasoned mechanics and determined DIYers.
Case Study: The Ghost in the Machine
I remember a 1998 Chevy C1500 that came into my bay with an intermittent stalling problem that was driving the owner crazy. He had already replaced the fuel pump and filter based on a friend’s advice, but the truck would still die randomly at stoplights. After hooking up my scan tool, I noticed erratic data from the crank sensor, but the sensor itself tested fine. Experience told me to look at the PCM. The internal drivers that process the sensor signals were failing intermittently. We installed a VIN-programmed PCM just like this one, and the truck ran perfectly. It’s a classic example of how a faulty computer can mimic a mechanical failure, and why replacing the core component is the right fix.
Is Your Truck Showing These Telltale Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution:
- âś” Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error), P0604, or P0606.
- âś” Vehicle will not start or is very difficult to start.
- âś” Intermittent stalling or cutting out while driving.
- âś” Noticeable decrease in fuel mileage.
- âś” Harsh or erratic automatic transmission shifting.
- âś” Failure to pass an emissions or smog test.
- âś” Apparent loss of engine power or poor acceleration.
A Straightforward Guide to Your PCM Swap
Installing your new 1998-1999 GMC 2500 PCM is a manageable job for most home mechanics. Following these steps will ensure a smooth process. Always consult a service manual for your specific vehicle if you are unsure.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unclip and remove the electrical wiring harnesses connected to the old PCM. These connectors have locking tabs that need to be released before pulling. Do not force them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in place by a few small bolts.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses into the new PCM until they click into place. Reconnect the negative battery terminal.
- Security Relearn (If Necessary): In many cases, the vehicle will start and run immediately. Some GM vehicles of this era may require a simple security relearn procedure, which typically involves cycling the key in the ignition. Instructions are readily available online for your specific model.
By purchasing this pre-programmed 1998-1999 GMC 2500 PCM, you’re not just buying a part; you’re buying a solution that saves you time, money, and the headache of a dealership visit.
Verified Vehicle Compatibility List
This module, identified by service number 09355699, is a direct replacement for several part numbers and fits a wide range of GM vehicles. Please match your part number or verify your vehicle is on this list to ensure proper fitment. This unit replaces: 16266645, 9355699, 16250279, 16258815, 09366810, 9366810.
- âś” 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickups (Gasoline)
- âś” 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- âś” 1998-1999 Chevrolet & GMC Suburban (Gasoline)
- âś” 1998-1999 Chevrolet Express & GMC Savana 1500/2500/3500 Vans (Gasoline)
- âś” 1999 Cadillac Escalade
- âś” 1998 Chevrolet Astro & GMC Safari
- âś” 1998 Oldsmobile Bravada
- âś” 1998 Chevrolet S10, GMC Sonoma, Oldsmobile Jimmy, Chevrolet Blazer
- âś” 1998 Isuzu Hombre (4.3L)
Frequently Asked Questions
Frequently Asked Questions
Do I need to program this computer?
No. We program the computer for you using the VIN you provide during checkout. It arrives ready for installation, requiring no further programming.
What is a VIN and where do I find it?
The VIN is your 17-digit Vehicle Identification Number. It’s typically found on a plate on the driver’s side dashboard (viewable through the windshield) or on the sticker in the driver’s side door jamb.
Is this a new part?
No, this is a high-quality, tested, and guaranteed functional computer recovered from a salvaged vehicle. This allows us to offer a reliable OEM part at an affordable price.
How do I know if my PCM is bad?
Common symptoms include a check engine light with codes like P0601, intermittent stalling, no-start conditions, and poor engine performance. While other parts can cause similar issues, these are strong indicators of PCM failure in these vehicles.
What is the security relearn procedure?
For some GM vehicles, you may need to help the vehicle’s anti-theft system recognize the new PCM. This is usually a simple 10-30 minute process of cycling the key in the ignition. Specific instructions for your model are widely available online or in service manuals.