Restore Peak Performance to Your GM Vehicle
Is your GMC Safari, Chevy Express, or Suburban running rough, stalling unexpectedly, or throwing a persistent check engine light? As a technician with over two decades of experience under the hood, I’ve seen these symptoms countless times. Often, the culprit is a failing Powertrain Control Module (PCM)—the electronic brain of your vehicle. A faulty PCM can cause a cascade of frustrating issues, from poor fuel economy and erratic shifting to a complete no-start condition. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded.
This isn’t just any replacement part. This is a dependable, OEM engine computer, part number 9366810, sourced from a vehicle that is no longer in service. The real value is in our service: before we ship it, we program the module with the latest official GM software updates, specifically matched to your vehicle’s VIN. This means it arrives at your door ready to install, saving you a costly trip to the dealership and the hassle of coordinating programming. You get a reliable part that communicates flawlessly with your truck or van, just as it was designed to.
A Technician’s Notebook: The Intermittent Stall Case
I remember a 1998 Chevy Express 2500 that came into my bay with a problem that was driving the owner crazy. It would run fine for days, then suddenly stall at a stoplight and refuse to restart for 10-15 minutes. There were no consistent trouble codes, just a history of random communication errors. We checked the fuel pressure, spark, and all the usual suspects—everything looked good. On a hunch, I tapped the PCM with a screwdriver handle while the engine was idling, and it immediately stumbled. The internal connections were failing intermittently. We replaced it with a VIN-programmed module just like this one, and the van ran reliably for years afterward. That’s the difference a solid PCM makes.
Is Your GM Truck or Van Showing These Symptoms?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, it might be time for a replacement:
- ✔ Check Engine Light is on with communication-related Diagnostic Trouble Codes (DTCs) like P0601, P0605, or U-series codes.
- ✔ The engine cranks but won’t start.
- ✔ Rough or inconsistent engine idle.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ The transmission isn’t shifting properly or feels erratic.
- ✔ Your vehicle fails an emissions test.
- ✔ Intermittent stalling for no apparent reason.
A Straightforward Guide to Installation
This module is designed for a direct swap. While specific locations vary slightly by model, the process is generally the same. For a 1998 GMC Safari, you’ll find it in the engine compartment by the battery.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on electrical components.
- Locate the PCM: Find the existing module in your engine bay. It’s a metal box with several large multi-pin electrical connectors.
- Disconnect and Remove: Carefully unplug all electrical connectors. They have locking tabs that need to be released. Once unplugged, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, programmed PCM into place. Reconnect all the electrical connectors, ensuring they click securely into position.
- Reconnect Battery: Reattach the negative battery terminal.
- Security Relearn (If Necessary): On some GM vehicles, you may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the vehicle’s anti-theft system to recognize the new PCM.
Verified Vehicle Compatibility
This PCM is a direct replacement for service ID number 9355699 and part number 9366810. It is compatible with a wide range of GM trucks, vans, and SUVs. Please verify your original part number or service ID to ensure a perfect match. This module fits the following vehicles:
- ✔ 1998-1999 Chevrolet & GMC Pickups (1500, 2500, 3500 Gasoline)
- ✔ 1998-1999 Chevrolet & GMC Suburban (1500, 2500 Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon
- ✔ 1998-1999 Chevrolet Express & GMC Savana Vans (1500, 2500, 3500 Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1999 Cadillac Escalade
- ✔ 1998 Oldsmobile Bravada
- ✔ 1998 GMC Envoy
- ✔ 1998 Chevrolet S10 / GMC Sonoma (4.3L)
- ✔ 1998 Chevrolet Blazer / GMC Jimmy (4.3L)
- ✔ 1998 Isuzu Hombre (4.3L)
Frequently Asked Questions
What do I need to do after I purchase this PCM?
After you place your order, you must provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We use this to program the module with the correct, updated software from GM before we ship it to you.
Will I need to do any additional programming?
No. The module arrives ready to install. In some cases, a simple security relearn procedure (which requires no special tools) may be necessary, as outlined in the installation steps.
What does ‘used’ condition mean for this part?
This is a genuine, factory OEM part that was carefully removed from a salvaged vehicle. Each unit is inspected and then fully programmed to function like new, providing OEM reliability at a fraction of the cost.
How do I find my original part number?
Your vehicle’s original PCM has a sticker on it that lists the part number and service ID number. We highly recommend matching the service ID (e.g., 9355699) for guaranteed compatibility.
Will this solve my check engine light problem?
If the check engine light is caused by an internal failure of your old PCM, then yes, this part will resolve the issue. It’s crucial to properly diagnose the problem first, as the light can be triggered by many other components.