Get Your Workhorse Van Back in Service, Fast
Is your 1998 or 1999 Chevy Express 3500 Van giving you headaches? Unexplained stalling, a persistent Check Engine Light, or a frustrating no-start condition can bring your work or travels to a grinding halt. As a technician with over two decades of experience, I’ve seen countless work vans sidelined by a faulty Powertrain Control Module (PCM). The PCM is the brain of your engine, and when it fails, it can cause a cascade of confusing and costly problems. This isn’t just an inconvenience; it’s lost time and money.
We offer a dependable and straightforward solution: a genuine, used OEM PCM, meticulously tested and programmed specifically for your vehicle. Simply provide your van’s VIN at checkout, and we’ll flash the module with the latest GM software updates. This ensures it communicates perfectly with your engine and transmission, restoring the performance and reliability you depend on. This is the exact service a dealership would perform, but without the high cost and scheduling delays. With our pre-programmed 1998-1999 Express 3500 PCM, you get a reliable part that’s ready to install right out of the box.
A Technician’s Notebook: The Intermittent No-Start
I remember a 1999 Express 3500 that came into the shop on a tow truck. The owner, a plumber, said it would randomly refuse to start. Sometimes it was fine for a week, then it would leave him stranded at a job site. He had already replaced the battery, starter, and fuel pump. My scan tool couldn’t communicate with the PCM, a classic red flag. After checking the power and ground circuits to the module, it was clear the PCM itself was failing internally. We installed one of our pre-programmed modules, performed the security relearn, and the van fired up instantly. He called a month later to say it hadn’t missed a beat since. That’s the difference a reliable PCM makes.
Is Your Van Exhibiting These PCM Failure Signs?
- ✔ Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module Read Only Memory (ROM) Error).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially when warm.
- ✔ Noticeably poor fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions or smog test.
- ✔ Your diagnostic scan tool cannot communicate with the PCM.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- ✔ Locate the PCM: On the 1998-1999 Express 3500 Van, the PCM is typically located in the engine compartment on the driver’s side, near the firewall or inner fender.
- ✔ Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harnesses from the old PCM. Inspect the connectors for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the mounting hardware as you will reuse it.
- ✔ Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- ✔ Reconnect Everything: Firmly plug the wiring harnesses back into the new PCM until they click into place. Reconnect the negative battery terminal.
- ✔ Perform Security Relearn: You will likely need to perform a simple security relearn procedure (often called VATS or Passlock relearn) to sync the new PCM with your vehicle’s anti-theft system. This procedure typically takes about 30 minutes and does not require special tools.
Verified Vehicle Compatibility
This module is a direct fit for a wide range of GM trucks and vans. It is a replacement for part numbers 09355699, 16266645, 16250279, 16258815, and 09366810. Please verify your vehicle is on this list and that the ID on your original module matches.
- Chevrolet Astro Van (1998)
- Oldsmobile Bravada (1998)
- Chevrolet Blazer S10 / GMC Jimmy S15 (1998)
- Cadillac Escalade (1999)
- Chevrolet / GMC C/K 1500, 2500, 3500 Pickups (1998-1999)
- Chevrolet / GMC Suburban 1500, 2500 (1998-1999)
- Chevrolet Tahoe / GMC Yukon (1998-1999)
- Chevrolet Express 1500, 2500, 3500 Vans (1998-1999)
- GMC Savana 1500, 2500, 3500 Vans (1998-1999)
- GMC Safari Van (1998)
- Isuzu Hombre (1998)
- Chevrolet S10 / GMC Sonoma (1998)
Frequently Asked Questions
How does the VIN programming work?
After you complete your purchase, you will need to provide us with your vehicle’s 17-digit VIN. We use this number to access the latest official GM software updates for your specific vehicle configuration. We then flash this software onto the module before shipping it to you, ensuring it’s a true plug-and-play part.
Is this a new part?
No, this is a high-quality, used OEM part sourced from a salvaged vehicle. Each unit is thoroughly inspected and tested to ensure full functionality before being programmed and shipped. This provides OEM reliability at a significant cost saving compared to a new dealership part.
Will I need to do anything else after installation?
In most cases, you will need to perform a security relearn procedure. This is a simple process that syncs the new PCM to your van’s anti-theft system. It typically involves turning the key to the ‘ON’ position for 10 minutes, ‘OFF’ for 10 seconds, and repeating this cycle three times. Instructions are readily available online for your specific model.
What if my part number is slightly different?
This PCM, identified by service ID 9355699, directly replaces several other part numbers including 09366810, 16266645, 16250279, and more. As long as your vehicle is on our compatibility list, this module will function correctly once programmed to your VIN.
Do I need to send my old PCM (core) back?
No core charge or return is required for this part. You can keep or responsibly dispose of your old module.