Get Your Workhorse Back on the Road with a Reliable, Programmed PCM
As a technician with over two decades of experience, I know the frustration that comes with a failing Powertrain Control Module (PCM). Your 1998-1999 GMC Savana 3500 Van is the backbone of your business or your go-to vehicle for heavy-duty tasks, and when it’s down, everything stops. A faulty PCM can cause a cascade of confusing problems, from a simple check engine light to a complete no-start condition. This isn’t just an inconvenience; it’s a hit to your productivity and peace of mind.
This is a dependable, used OEM PCM, part number 9355699, that has been carefully sourced and tested. More importantly, it arrives at your door ready to install. We handle the critical step of programming it with the latest GM software updates, specifically matched to your vehicle’s VIN. This means you can bypass the expensive and time-consuming trip to the dealership for programming. You get a cost-effective solution that restores your van’s original performance and reliability.
Is Your GM Truck or Van Showing These Symptoms?
A failing PCM, the ‘brain’ of your vehicle, can manifest in numerous ways. Over the years in my shop, I’ve seen these modules cause some of the most difficult-to-diagnose issues. If you’re experiencing any of the following, a faulty PCM could be the culprit:
- ✔ Unexplained Check Engine Light with codes like P0601, P0604, or P0605 (Internal Control Module Errors).
- ✔ Engine cranks but refuses to start.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Sudden stalling or intermittent stumbling while driving.
- ✔ Noticeable decrease in fuel economy.
- ✔ Communication errors with your scan tool.
- ✔ Misfire codes that persist even after replacing plugs, wires, and coils.
From the Diagnostic Bay: The Intermittent No-Start Mystery
A customer brought in his ’99 Chevy Express 3500, a sister vehicle to the Savana, with an intermittent no-start that was driving him crazy. It would be fine for a week, then leave him stranded. No codes were stored. We checked fuel pressure, spark, and all the basics—everything looked good. During one of its ‘no-start’ episodes, I noticed the security light was flashing and my high-end scan tool couldn’t communicate with the 1998-1999 Savana 3500 PCM. That was the key. The PCM itself was failing internally, occasionally losing its ability to communicate and recognize the security key. A replacement, programmed PCM like this one solved the problem instantly and permanently.
A Straightforward Guide to Installation
Installing this module is a manageable job for a confident DIYer or any professional mechanic. Because we program it beforehand, you won’t need any special scan tools for setup.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998-1999 Savana and Express vans, the PCM is located in the engine compartment, on the driver’s side, often near the battery or firewall.
- 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.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new module.
- Install the New PCM: Mount your new, pre-programmed PCM using the original hardware. Ensure it is secure.
- Reconnect Everything: Plug the wiring harnesses firmly into the new module. You should hear a ‘click’ as they lock into place. Reconnect the negative battery terminal.
- Security Relearn (If Necessary): In many cases, the vehicle will start right up. However, some GM vehicles of this era require a simple security relearn procedure. Turn the key to the ‘ON’ position (without starting) for 10-15 minutes, then turn it ‘OFF’ for 10 seconds. Repeat this cycle 3 times. On the fourth try, the vehicle should start.
Verified Vehicle Compatibility
This PCM, identified by service number 9355699, is a direct replacement for a wide range of GM trucks and vans. Please match your part number to ensure compatibility. This module fits the following vehicles with ID 9355699:
- GMC Savana 3500 Van: 1998, 1999 (Gasoline)
- Chevrolet Express 3500 Van: 1998, 1999 (Gasoline)
- GMC/Chevrolet Pickups (1500, 2500, 3500): 1998-1999 (Gasoline)
- GMC/Chevrolet Suburban (1500, 2500): 1998-1999 (Gasoline)
- GMC Yukon / Chevrolet Tahoe: 1998-1999 (Gasoline)
- Cadillac Escalade: 1999
- GMC Savana / Chevrolet Express (1500, 2500): 1998-1999 (Gasoline)
- GMC Safari / Chevrolet Astro: 1998
- Oldsmobile Bravada / GMC Envoy: 1998 (4.3L)
- Chevrolet S10 / GMC Sonoma / Isuzu Hombre: 1998 (4.3L)
- Chevrolet Blazer / GMC Jimmy: 1998 (4.3L)
- This module also replaces part numbers: 16266645, 16250279, 16258815, 09366810.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, correct GM-certified software for your van’s specific engine, transmission, and options. This ensures perfect compatibility and function right out of the box, eliminating the need for dealer programming.
Is this a plug-and-play part?
Yes! Because we pre-program the module to your VIN, it is designed to be a plug-and-play solution. In some cases, a simple 30-minute security relearn procedure (as described in the installation guide) may be required, which involves no special tools.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This provides an affordable and reliable alternative to a costly new module from a dealership.
Will this fix my check engine light?
If the check engine light and performance issues are caused by a faulty PCM (e.g., internal processor error codes), then this part is the correct fix. It’s crucial to properly diagnose the vehicle first, as other failing sensors or components can cause similar symptoms.
How do I provide my VIN after purchase?
After completing your purchase, simply send us a message with your 17-digit VIN. We cannot ship the module until we receive this information, as the programming is a critical part of your order.