Get Your Workhorse Van Running Right Again
Is your 1998-1999 GMC Savana 1500 van giving you headaches? Stalling at red lights, shifting erratically, or just refusing to start? A faulty Powertrain Control Module (PCM) is often the culprit behind these frustrating and unpredictable issues. As the brain of your vehicle, when the PCM starts to fail, it can affect everything from fuel economy to engine performance. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded. This replacement PCM, part number 9366810, is the reliable, cost-effective solution to restore your van’s performance and get you back on the road with confidence.
What sets this module apart is our commitment to a true plug-and-play experience. We don’t just ship you a part; we provide a fully programmed solution. Before this genuine used OEM computer leaves our facility, we flash it with the latest GM software updates specific to your vehicle’s VIN. This critical step ensures seamless communication between the engine, transmission, and other onboard systems, eliminating the need for an expensive trip to the dealership for programming. It’s the same level of precision you’d expect from a professional shop, delivered right to your door.
From the Diagnostic Bay: The Heat Soak Problem
In my 20+ years turning wrenches, I’ve seen countless late-90s GM vans and trucks roll in with baffling electrical gremlins. A common scenario I remember was a 1999 Express van used for a delivery service. It would run perfectly fine for the first 20 minutes, but after a few stops in summer heat, it would start stumbling, misfiring, and eventually stall. After cooling down for an hour, it would fire right back up. This classic heat-soak failure points directly to the PCM. The internal solder joints and electronic components on these older modules break down from years of heat cycles in the engine bay. Swapping in a quality, tested PCM like this one was the definitive fix every time.
Is Your Savana Van Showing These PCM Failure Signs?
A failing computer can manifest in various ways. If you’re experiencing any of the following, it’s a strong indicator that your PCM needs replacement:
- âś” Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or other communication errors.
- âś” The engine cranks but refuses to start.
- âś” Unexplained stalling or rough idling, especially after the engine warms up.
- âś” Harsh or erratic automatic transmission shifting.
- âś” A noticeable drop in fuel efficiency.
- âś” Failure to pass an emissions or smog test.
- âś” Intermittent loss of power or hesitation during acceleration.
Your Straightforward PCM Installation Guide
Installing your new PCM is a manageable job for a DIYer with basic tools. Follow these steps carefully for a smooth installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental power surges.
- Locate the PCM: On the 1998-1999 Savana/Express vans, the PCM is typically located in the engine compartment on the left-hand (driver’s) side, near the rear of the engine.
- Disconnect the Wiring: Carefully unplug the electrical connectors from the old PCM. These connectors have locking tabs that may need to be squeezed or lifted to release. Never force them. Inspect the connectors for any corrosion or bent pins.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you’ll need it to install the new unit.
- Install the New PCM: Mount your replacement PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click into place. Reconnect your vehicle’s negative battery terminal.
- Security Relearn (Important!): After installation, you will likely need to perform a security relearn procedure (often called a Passlock or VATS relearn) to allow the vehicle to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating this cycle 2-3 times. Your vehicle’s service manual will have the specific steps.
Verified Fitment For Your GM Truck or Van
This module, identified by service ID 9355699, is a direct replacement for a wide range of GM vehicles. While this listing is for the 1998-1999 Savana 1500 PCM, it also fits many other models. Please match your part number or ID to ensure compatibility. This unit is interchangeable with part numbers 09355699, 16266645, 16250279, 16258815, and 9366810. It is compatible with dozens of vehicles including the Chevy Express, Suburban, Tahoe, C/K Pickups, GMC Yukon, and more from this era. Please consult the detailed fitment list to confirm it’s the right part for your truck or van.
Frequently Asked Questions
Do I need to do anything after I buy it?
Yes. After your purchase, you must send us your vehicle’s 17-digit VIN. We cannot program and ship the module without it. This ensures the PCM has the correct software for your specific vehicle configuration.
Is this a new part?
No, this is a high-quality, genuine OEM part that has been sourced from a salvaged vehicle. Each unit is inspected and tested to ensure full functionality before being programmed and shipped.
Will I need a mechanic to install this?
While the physical swap is straightforward for many DIYers, some vehicles require a security relearn procedure after installation for the engine to start. We provide general instructions, but you should be comfortable with this process or have a mechanic available to assist if needed.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM (Engine Control Module) typically just controls engine functions. A PCM (Powertrain Control Module) controls both the engine and the transmission, which is standard on most vehicles like your Savana van.
Does this part require any additional programming?
No. We handle all the programming before we ship it. It will arrive ready to be installed in your vehicle. The only additional step you may need to perform is the security relearn, which does not require special tools.