Is Your 1998-1999 GMC Savana 1500 Running Rough?
If you’re dealing with frustrating engine problems like stalling, a persistent check engine light, or a no-start condition, the heart of the issue might be a failing Powertrain Control Module (PCM). As a seasoned technician, I’ve seen countless GM vans and trucks from this era sidelined by a faulty computer. The PCM is the brain of your vehicle, controlling everything from fuel mixture and ignition timing to transmission shifting. When it fails, your workhorse van can become unreliable or completely undrivable.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We offer a quality, tested used 1998-1999 Savana 1500 PCM that solves the biggest headache of this repair: programming. Before we ship this module, our experts will flash it with the latest official GM software updates, tailored specifically to your van using the Vehicle Identification Number (VIN) you provide. This ensures optimal performance, fuel efficiency, and compatibility, eliminating the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay: The Intermittent Stall
I remember a 1999 Express van (which uses the same PCM as the Savana) that came into my shop with a maddening intermittent stalling issue. The owner, a plumber, said it would die at stoplights only after it was fully warmed up. No codes were stored initially. After letting it run in the bay for 45 minutes, it finally stalled and threw a P0601 (Internal Control Module Memory Check Sum Error). These older PCMs are notorious for failing under heat soak. The internal solder joints and processors degrade over 20+ years of heat cycles in the engine bay. We swapped in a VIN-programmed module like this one, performed the quick security relearn, and the van ran perfectly. It’s a classic failure mode for these reliable but aging vehicles.
What Are the Signs of a Failing PCM?
- ✔ Check Engine Light is on with codes like P0601, P0604, or P0606.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle stalls unexpectedly, especially when warm.
- ✔ Communication errors with your OBD-II scan tool.
A Straightforward Guide to Installation
Replacing the PCM in your Savana is a manageable job for a DIYer. Our pre-programmed module makes it even simpler. While specific steps can vary slightly, here is a general guide:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On the 1998-1999 Savana/Express vans, the PCM is typically located in the engine compartment on the driver’s side, often near the battery or on the fender well.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are usually a few bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will likely need to perform a simple security relearn procedure (often called the Passlock or CASE relearn) so the vehicle recognizes the new computer. This procedure typically involves turning the key to the ‘ON’ position for 10-15 minutes and can be done without special tools. We include instructions for this process.
Guaranteed Vehicle Compatibility
This module is a direct replacement for service number 9366810 and is interchangeable with part numbers 09355699, 16266645, 16250279, and 16258815. It is confirmed to fit a wide range of GM trucks, vans, and SUVs from the 1998-1999 model years. Please match your part number or verify fitment with the list below. This module fits many popular vehicles including the Chevrolet Express, GMC Safari, Cadillac Escalade, Chevy/GMC Pickups (1500, 2500, 3500), Suburban, Tahoe, and Yukon.
Frequently Asked Questions
Frequently Asked Questions
Do I really need to provide my VIN?
Yes, absolutely. Providing your 17-digit VIN is critical. We use it to load the exact, correct GM factory software for your van’s specific engine, transmission, and options. This ensures a true plug-and-play experience and proper vehicle operation.
Is any additional programming needed after installation?
Our pre-flashing service handles the main programming. However, you will need to perform a security relearn procedure (also known as a CASE relearn or Crankshaft Variation relearn). This is a simple process that syncs the new PCM to your vehicle’s anti-theft and crankshaft position sensor systems. We provide easy-to-follow instructions.
This part is listed as ‘used’. How can I trust it?
Each module is sourced from a salvaged vehicle and then subjected to a thorough bench test to ensure full functionality of all circuits. We only sell units that pass our strict quality control standards. This gives you a reliable part at a fraction of the cost of a new one.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM also functions as the transmission control module (TCM) in these vehicles. If your shifting issues are caused by faulty electronic commands from the computer, this replacement module will resolve them. However, it will not fix internal mechanical problems within the transmission itself.
What is the process after I place my order?
After you complete your purchase, you will need to send us your vehicle’s VIN. Once we receive the VIN, our technicians will program the module within 1-2 business days and then ship it directly to you.