Restore Peak Performance to Your GM Truck or Van
Is your trusty Chevrolet Express or GMC Savana suddenly running rough, stalling, or throwing confusing check engine light codes? You’re not just losing time; you’re losing confidence in your vehicle. As a technician with over two decades of experience, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can cause a cascade of frustrating, hard-to-diagnose issues. It’s the brain of your engine, and when it falters, everything from fuel economy to shift points can go haywire. This isn’t just an inconvenience—for a work van, it’s a direct hit to your bottom line.
This is your straightforward, reliable solution. We offer a genuine, used OEM PCM, part number 09355699, that serves as the heart of many iconic late-90s GM trucks and vans. The best part? It arrives at your door completely programmed to your vehicle’s specific Vehicle Identification Number (VIN). We handle the complex part by flashing it with the latest official GM software updates, so you can skip the expensive trip to the dealership. This ensures all factory parameters for your engine and transmission are perfectly restored, making the installation process as simple as possible.
A Technician’s Notebook: The Intermittent Stall
I remember a 1999 Suburban that came into the shop with a problem that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a stoplight and refuse to restart for 10-15 minutes. No consistent codes, just pure frustration. After checking fuel pressure, spark, and sensors, everything seemed fine. On a hunch, I monitored the PCM data stream during a long test drive. Right before it stalled, the data went haywire. The internal processor was failing under heat. We installed a VIN-programmed PCM just like this one, and the problem vanished instantly. It’s a classic failure mode for these units, and this is the definitive fix.
Is Your Vehicle Showing These Telltale Signs?
A failing PCM can manifest in several ways. If you’re experiencing any of the following, this module is a likely culprit. This is especially true if you see diagnostic trouble codes (DTCs) like P0601 or P0606, which point directly to an internal computer fault.
- ✔ Check Engine Light is on or flashes intermittently.
- ✔ Vehicle fails to start or has a hard starting condition.
- ✔ Engine stalls unexpectedly while driving or at idle.
- ✔ Noticeable decrease in fuel economy.
- ✔ Rough or unstable engine idle.
- ✔ Automatic transmission shifts harshly, late, or not at all.
- ✔ Communication errors with your scan tool.
DIY-Friendly Installation Guide
Installing your programmed 1998-1999 Express 3500 PCM is a job most DIYers can handle in under an hour with basic hand tools. Since we’ve already done the programming, you won’t need any specialized computer equipment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On most of these GM trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old PCM. These connectors have locking tabs; be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket. Firmly reconnect the electrical harnesses, ensuring they click securely into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Security Relearn Procedure: In some cases, you may need to perform a simple security relearn. Turn the key to the ‘ON’ position for 10-15 minutes, then turn it off for 10 seconds. Repeat this cycle three times. On the fourth try, the vehicle should start and run normally.
Guaranteed Fitment for Your GM Vehicle
This module, identified by part number 09355699, is a direct replacement for a wide range of GM vehicles. Please verify your original part number or match your vehicle from the list below to ensure compatibility. This unit is interchangeable with part numbers: 16266645, 16250279, 16258815, and 09366810.
EXPRESS 2500 VAN 98 Electronic Control Module; gasoline, ID 9355699
SAVANA 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 9355699
ESCALADE 99 Electronic Control Module; (LH front engine compartment), ID 9355699
SAFARI (GMC) 98 Electronic Control Module; (LH front by battery), ID 9355699
SAVANA 1500 VAN 98 Electronic Control Module; ID 9355699
SUBURBAN 1500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
ASTRO 98 Electronic Control Module; (LH front by battery), ID 9355699
SAVANA 3500 VAN 98 Electronic Control Module; gasoline, ID 9355699
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/o build date opt ZN4; ID 9355699
EXPRESS 1500 VAN 98 Electronic Control Module; ID 9355699
SAVANA 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 9355699
TAHOE 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
YUKON 98-99 Electronic Control Module; (LH engine compartment), ID 9355699
CHEVROLET 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
SUBURBAN 2500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 9355699
GMC 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 9355699
CHEVROLET 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
EXPRESS 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 9355699
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/o extended build date opt ZN4; ID 9355699
EXPRESS 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 9355699
EXPRESS 3500 VAN 98-99 Electronic Control Module; gasoline, ID 9355699
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/o build date opt ZN4; ID 9355699
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
GMC 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 9355699
SAVANA 3500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 9355699
GMC 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
GMC 1500 PICKUP 98 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
GMC 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
Don’t let a faulty computer keep your vehicle off the road. Order this pre-programmed 1998-1999 Express 3500 PCM and restore the dependable performance you rely on.
Frequently Asked Questions
Why do you need my VIN?
Your VIN (Vehicle Identification Number) is essential. It allows us to load the exact GM-specified software for your vehicle’s engine, transmission, and options. This ensures perfect compatibility and function without requiring a trip to the dealer.
Is this part difficult to install?
Not at all. For most DIYers with basic tools, this is a simple plug-and-play replacement. Since we do the programming, you just need to swap the physical module. We include a basic installation guide and security relearn procedure to help you.
What is a security relearn?
It’s a simple process that syncs the new PCM with your vehicle’s anti-theft system (PassLock/VATS). It typically involves cycling the ignition key and waiting, requiring no special tools. We provide instructions for this.
This computer is used. Is it reliable?
Yes. We source genuine OEM modules from salvaged vehicles. Each unit is inspected and then flashed with the latest stable software from GM, which often corrects factory bugs. This provides a reliable and cost-effective solution compared to a new dealership part.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like DTC P0601), then yes, this will resolve the issue. However, if the code is for a faulty sensor (like an O2 sensor), you will still need to replace that sensor. This PCM will correctly process signals from new, working sensors.