Is Your Work Van Unreliable? Get Back on the Job Fast.
As a technician with over two decades of experience, I know the frustration of a vehicle that won’t run right. For workhorse vans like the 1998-1999 GMC Savana 3500, a faulty Powertrain Control Module (PCM) can mean lost time and lost income. Symptoms like stalling, erratic shifting, a persistent Check Engine Light, or a no-start condition often point directly to the vehicle’s brain. This isn’t just an inconvenience; it’s a critical failure that sidelines your business or your project.
This is a reliable, tested, used OEM PCM, part number 09355699, that serves as a direct-fit replacement. The most significant benefit we offer is our professional programming service. Before we ship the module, we flash it with the latest GM-certified software updates, specifically calibrated to your vehicle using the VIN you provide. This critical step ensures the module communicates perfectly with your engine, transmission, and anti-theft system, making the installation process as close to plug-and-play as possible and saving you from a costly trip to the dealership for programming.
From the Diagnostic Bay
I remember a 1999 Express 3500 that came into my shop. The owner, a plumber, was at his wit’s end. The van would randomly die at stoplights and had a harsh 1-2 shift. He’d already replaced the fuel pump and a few sensors with no luck. After connecting my scan tool, I pulled a P0601 code (Internal Control Module Memory Check Sum Error). This is a dead giveaway for a failed PCM. The internal memory was corrupted, causing all sorts of phantom issues. We installed a VIN-programmed PCM just like this one, and the van ran like it was new. It’s a classic example of how a single component can mimic a dozen other problems, and why a correct diagnosis is key.
Diagnosing a Faulty PCM on Your GM Van or Truck
A failing computer can be tricky to diagnose because its symptoms can overlap with other failing parts. However, after years of working on these specific GM platforms, I’ve seen a clear pattern. If your vehicle is experiencing a combination of the issues below, the PCM is a highly likely culprit. A faulty 1998-1999 Savana 3500 PCM can cripple your vehicle’s performance and reliability.
Telltale Signs of a Failing Module
- ✔ Check Engine Light is on with codes like P0601, P0602, P0604, or P0605.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially after warming up.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with your scan tool.
- ✔ The anti-theft or security light stays on, preventing startup.
A Straightforward Guide to Installation
Replacing the PCM on these GM vehicles is a job most DIYers can handle with basic tools. Our VIN programming service eliminates the most complicated step. Here is a general guide to get you started:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most Savana/Express vans, the PCM is located in the engine compartment, typically on the driver’s side near the battery or airbox. It’s a silver metal box with multiple large wiring harness connectors.
- Disconnect the Harnesses: Carefully release the locking tabs on each electrical connector and pull them straight out from the module. Avoid pulling on the wires themselves.
- 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 PCM: Mount your new, pre-programmed PCM onto the bracket and secure the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the correct sockets until they click into place. Reconnect the negative battery terminal.
- Final Check: You may need to perform a security relearn procedure, which is a simple process involving turning the key on and off. Instructions are readily available online for your specific model. Start the vehicle and check for proper operation.
Verified Vehicle Compatibility
This module, identified by part number 09355699, is a direct replacement for a wide range of GM trucks and vans. Please verify your original part number or consult the list below. This part is interchangeable with service numbers: 16266645, 16250279, 16258815, and 09366810.
CHEVROLET EXPRESS / GMC SAVANA 1500/2500/3500 VAN (1998-1999, Gasoline)
CADILLAC ESCALADE (1999)
CHEVROLET TAHOE / GMC YUKON (1998-1999, Gasoline)
CHEVROLET / GMC SUBURBAN 1500/2500 (1998-1999, Gasoline)
CHEVROLET ASTRO / GMC SAFARI (1998)
OLDSMOBILE BRAVADA (1998)
GMC ENVOY (1998)
CHEVROLET S10 / GMC SONOMA (1998, 4.3L)
CHEVROLET BLAZER / GMC JIMMY (1998)
ISUZU HOMBRE (1998, 4.3L)
Note: This is a comprehensive list. Always match the ID number 09355699 from your original module to ensure perfect compatibility.
Frequently Asked Questions
What is VIN programming and why do I need it?
What is VIN programming and why do I need it?
VIN programming is the process of loading your vehicle’s specific software onto the PCM. This includes information about your engine, transmission, options, and anti-theft system (PassLock/VATS). Without it, the vehicle will not start or run correctly. We handle this for you before shipping.
How do I send you my VIN?
After you complete your purchase, you can add your 17-digit VIN to the order notes or send it to us through the messaging system. We cannot ship your order until we receive your VIN.
Is this a used part?
Yes, this is a genuine OEM part that has been carefully sourced from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional before being programmed and shipped. This provides OEM reliability at a significant cost savings over a new part.
Will I need to do anything else after installing this 1998-1999 Savana 3500 PCM?
In most cases, no further programming is needed. However, on these GM vehicles, you will likely need to perform a simple security relearn procedure. This can be done without any special tools and typically involves cycling the ignition key. It syncs the programmed PCM to your vehicle’s anti-theft system.
What if my part number is slightly different?
This module, 09355699, is a direct replacement for several other part numbers, including 16266645, 16250279, and more as listed in our compatibility section. As long as your vehicle is on the fitment list and your original module carries one of these numbers, this part will work correctly.