Restore Peak Performance to Your GM Truck or Van
Is your trusty GMC or Chevy truck suffering from perplexing issues like stalling, erratic shifting, a persistent Check Engine Light, or poor fuel mileage? Before you suspect a dozen different sensors or mechanical failures, the real culprit is often the vehicle’s brain: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless vehicles with these exact symptoms, and a failing PCM is one of the most common, yet frequently misdiagnosed, problems on these late-90s GM platforms.
This isn’t just a replacement part; it’s a direct solution. We offer a genuine, used OEM PCM that has been meticulously tested and is ready for installation. The most critical service we provide is programming this module specifically to your vehicle’s Vehicle Identification Number (VIN) before it ships. This means it arrives at your door with the latest GM software updates already loaded, eliminating the need for an expensive trip to the dealership for programming. You get a reliable, plug-and-play fix that restores your vehicle’s engine management system to its original factory specifications.
A Technician’s Notebook: The Ghost in the Machine
I remember a 1999 Chevy Tahoe that came into my shop. The owner was frustrated; he’d replaced the fuel pump and multiple sensors, but the truck would still randomly stall at red lights and had a terrible hesitation on acceleration. No consistent codes were being stored, just a random misfire now and then. After confirming fuel pressure and spark were solid, I hooked up my high-level scan tool to monitor the PCM’s live data. I noticed the injector pulse width was fluctuating wildly for no reason. This pointed directly to a faulty processor inside the PCM. We swapped in a VIN-programmed module just like this one, and the truck ran perfectly. It’s a classic case where the issue isn’t mechanical, but electronic—a failing brain causing system-wide chaos.
Is Your Vehicle Showing These Symptoms?
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially when warm.
- ✔ A noticeable drop in fuel economy.
- ✔ The automatic transmission is shifting harshly or at the wrong times.
- ✔ Your Check Engine Light is on with codes like P0601, P0605, or P0606 (Internal Control Module Errors).
- ✔ The vehicle fails to communicate with a diagnostic scan tool.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for the system capacitors to discharge.
- ✔ Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- ✔ Disconnect the Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs; do not force them. Inspect the terminals for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few small bolts.
- ✔ Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- ✔ Reconnect Everything: Firmly press the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Steps: Some vehicles may require a security relearn procedure, which can often be done without special tools by cycling the key. Your vehicle’s service manual will have the specific steps if needed. Start the engine and enjoy your smooth-running truck!
Verified Vehicle Compatibility
This module, identified by service number 9355699, is a direct replacement for multiple part numbers including 09355699, 16266645, 16250279, 16258815, and 9366810. It fits a wide range of GM vehicles. Please verify your part number and check the list below. If your vehicle is on the list, this is the correct part for you.
- Astro / Safari (GMC): 1998
- Blazer S10 / Jimmy S15: 1998 (w/o build date opt ZN4)
- Bravada: 1998 (w/o build date opt ZN4)
- Cadillac Escalade: 1999
- Chevrolet / GMC 1500 Pickup: 1998-1999
- Chevrolet / GMC 2500 Pickup: 1998-1999 (Gasoline)
- Chevrolet / GMC 3500 Pickup: 1998-1999 (Gasoline)
- Envoy: 1998 (w/o build date opt ZN4)
- Express / Savana 1500 Van: 1998-1999
- Express / Savana 2500 Van: 1998-1999 (Gasoline)
- Express / Savana 3500 Van: 1998-1999 (Gasoline)
- Isuzu Hombre: 1998 (4.3L, w/o extended build date opt ZN4)
- S10 / S15 / Sonoma: 1998 (4.3L, w/o build date opt ZN4)
- Suburban 1500/2500: 1998-1999 (Gasoline)
- Tahoe / Yukon: 1998-1999 (Gasoline)
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, simply send us a message with your vehicle’s 17-digit VIN. We cannot ship the module until we receive this information.
Is this part difficult to install myself?
No, this is a very DIY-friendly repair. As long as you can disconnect a battery and use a basic wrench to remove a few bolts, you can do this job. Our pre-programming saves you the most complicated step.
What does ‘used’ mean for an electronic part?
This is a genuine OEM part sourced from a salvaged vehicle. Unlike aftermarket parts, it was built to GM’s original quality standards. Each unit is inspected and tested to ensure full functionality before being programmed and shipped.
Will I need to do anything else after installation?
In most cases, no. It’s designed to be plug-and-play. On rare occasions, a ‘Case Learn’ or security relearn procedure may be needed, which is a simple process you can typically perform yourself. We recommend clearing any old trouble codes with a basic scanner after installation.
How do I know my old PCM is actually bad?
Common signs include a no-start condition with power to all other systems, persistent internal module error codes (like P0601), and erratic engine or transmission behavior that can’t be traced to a mechanical fault. If you’ve checked grounds, sensors, and wiring, the PCM is the next logical step.