Restore Peak Performance to Your GM Workhorse
If you’re dealing with frustrating issues like a check engine light that won’t go away, rough running, stalling, or poor fuel economy in your 1998 GMC Savana 3500 Van, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience, I’ve seen these exact symptoms hundreds of times on this generation of GM trucks and vans. The PCM is the brain of your vehicle’s engine and transmission, and when it starts to fail, it can cause a cascade of problems that are difficult to trace. This isn’t just a replacement part; it’s a direct solution to restore your vehicle’s reliability and performance.
We take the guesswork and dealership hassle out of the equation. This module is not a blank slate. Before we ship it, our technicians will program it with the latest official GM software updates, specifically matched to your vehicle’s unique VIN. This ensures perfect compatibility and often corrects factory-level drivability issues you may have been living with for years. Getting your work van or truck back on the road shouldn’t require specialized tools or expensive dealer visits. This is the reliable, straightforward fix you’ve been looking for.
From the Diagnostic Bay: The Case of the Intermittent Stall
I remember a 1998 Chevy C2500 pickup—same platform as these vans—that came into my shop with a maddening intermittent stall. It only happened after it was driven for 30+ minutes and would restart fine after cooling down. The owner had already replaced the fuel pump and ignition control module. We checked grounds, wiring, and sensor data, but everything looked perfect. On a hunch, I used a heat gun on the PCM while the truck was idling. Within two minutes, the engine sputtered and died. The internal processor was failing under heat stress, a classic failure mode for these units. A pre-programmed replacement like this one had him back on the road permanently the next day. Sometimes, the simplest solution is the right one.
Is Your GM Truck or Van Showing These Symptoms?
A failing PCM can manifest in many ways. If your vehicle is experiencing any of the following, it might be time for a replacement 1998 Savana 3500 PCM:
- ✔ Check Engine Light is on with communication codes (U-codes) or internal module failure codes (P0601, P0602, P0605).
- ✔ The engine cranks but won’t start.
- ✔ Unexplained stalling or rough idling, especially when warm.
- ✔ Noticeably poor fuel mileage.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions/smog test.
- ✔ No communication with your scan tool.
A Straightforward Guide to Installation
You don’t need to be a master mechanic to install this module. With basic hand tools, you can get the job done right in your driveway. The most critical part is the security relearn procedure, which syncs the new PCM to your vehicle’s anti-theft system.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: On most of these GM vans and trucks, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Then, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed PCM into place. Reconnect the wiring harnesses, ensuring they click securely into place. Reconnect the negative battery terminal.
- Perform Security Relearn (CRITICAL): You must perform the GM VATS/Passlock relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle will not start until this is completed.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. It is guaranteed to fit the following vehicles with the specified options:
BLAZER S10/JIMMY S15 98 (RH front engine, w/o opt ZN4)
BRAVADA 98 (4.3L, w/o opt ZN4)
CHEVROLET 1500 PICKUP 98-99 (Gasoline, LH engine compartment)
CHEVROLET 2500 PICKUP 98-99 (Gasoline, LH front engine compartment)
CHEVROLET 3500 PICKUP 98-99 (Gasoline, LH front engine compartment)
ENVOY 98 (RH front engine, w/o opt ZN4)
ESCALADE 99 (LH front engine compartment)
EXPRESS 1500/2500/3500 VAN 98 (Gasoline)
GMC 1500 PICKUP 98-99 (Gasoline, LH engine compartment)
GMC 2500 PICKUP 98-99 (Gasoline, LH front engine compartment)
GMC 3500 PICKUP 98-99 (Gasoline, LH front engine compartment)
ISUZU HOMBRE 98 (4.3L, w/o opt ZN4)
S10/S15/SONOMA 98 (4.3L, w/o opt ZN4)
SAFARI (GMC) 98-99 (By battery)
SAVANA 1500/2500 VAN 98 (Gasoline)
SAVANA 3500 VAN 98 (Gasoline)
SUBURBAN 1500/2500 98-99 (Gasoline, LH front engine compartment)
TAHOE 98-99 (Gasoline, LH engine compartment)
YUKON 98-99 (LH engine compartment)
What does ‘programmed to my VIN’ mean?
What does ‘programmed to my VIN’ mean?
It means we load the module with the specific software calibration from General Motors that matches your vehicle’s Vehicle Identification Number (VIN). This ensures all systems, from the engine to the transmission and anti-theft system, function exactly as the factory intended.
Do I need to do anything after I install it?
Yes. After physical installation, you MUST perform the security relearn procedure (often called the VATS or Passlock relearn). This is a simple process that does not require any special tools and allows the new PCM to sync with your vehicle’s keys and anti-theft system. The vehicle will not start until this is completed.
Where is the PCM located on my 1998 Savana 3500 Van?
On the 1998 Savana and Express vans, the PCM is located inside the engine compartment on the driver’s side, mounted near the battery and master cylinder. It’s a silver metal box with several large wiring harness connectors.
Is this a brand new part?
This is a genuine OEM module that has been meticulously tested to ensure full functionality. It is then loaded with fresh, vehicle-specific software directly from GM’s library. This provides the reliability of an original part with the benefit of the latest software updates, all at a significant cost savings compared to a dealership.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM itself (common codes like P0601-P0606) or a software glitch corrected by the new programming, then yes, this will resolve the issue. However, if the light is on due to a faulty sensor or other mechanical problem, those issues will still need to be addressed separately.