Restore Your Van’s Core Performance and Reliability
Is your 1998-1999 GMC Savana 2500 van giving you headaches? Unexplained stalling, a persistent Check Engine Light, or erratic engine behavior can bring your work or travels to a grinding halt. As the central computer for your engine and transmission, a failing Powertrain Control Module (PCM) is often the culprit. This replacement PCM, part number 16266645, is a direct-fit, reliable solution to get your van running smoothly again. We take the guesswork and dealership expense out of the equation by programming the module to your vehicle’s specific VIN before it ships. This ensures proper communication with all other systems in your van right out of the box.
Case Study: A Tricky Diagnosis
I remember a customer with a ’99 Express van—same platform as the Savana—that had a ghost of a problem. It would run perfectly for days, then suddenly refuse to start, only to fire right up an hour later. No consistent codes, just frustration. After checking fuel pressure and spark, which were intermittent, we focused on the PCM. On these older GM vehicles, heat soak can cause microscopic cracks in the PCM’s circuit board. When the engine bay got hot enough, a connection would fail, killing the engine. Once it cooled, the connection would be restored. Swapping in a quality, pre-programmed PCM like this one solved the issue permanently. It’s a classic failure I’ve seen dozens of times, and it’s why confirming the PCM is the root cause is so important.
Is Your Van Showing These Symptoms?
- ✔ The Check Engine Light is on, and you may have codes like P0601, P0604, or P0605.
- ✔ Your engine cranks but refuses to start.
- ✔ The vehicle experiences random stalling or rough idling.
- ✔ You notice a sudden drop in fuel efficiency.
- ✔ The automatic transmission is shifting harshly or at the wrong times.
- ✔ You’ve failed an emissions test due to module communication errors.
Replacing a faulty module is critical. A bad PCM can leave you stranded and, in some cases, cause damage to other components like the catalytic converter due to an incorrect air/fuel mixture. This tested, VIN-programmed 1998-1999 Savana 2500 PCM is the dependable fix you need.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- ✔ Locate the PCM: On most Savana and Express vans, the PCM is located in the engine compartment on the driver’s side, near the air filter housing.
- ✔ Disconnect Connectors: Carefully unclip and remove the electrical wiring harnesses from the old PCM. These connectors have locking tabs that need to be released before pulling.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. There are typically a few bolts holding it in place.
- ✔ Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts.
- ✔ Reconnect Everything: Plug the wiring harnesses firmly into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Perform Security Relearn: You will need to perform a simple security relearn procedure so the vehicle recognizes the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Instructions will be included with your part.
Verified Vehicle Compatibility
This module, identified by service number 16266645 or ID 09355699, is a guaranteed fit for a wide range of GM trucks and vans. While this listing is for a 1998-1999 Savana 2500 PCM, it also fits the following vehicles. Please verify your part number or contact us with your VIN to ensure compatibility.
- Chevrolet Express / GMC Savana (1500, 2500, 3500): 1998-1999
- Chevrolet / GMC Pickups (1500, 2500, 3500): 1998-1999
- Chevrolet Suburban / GMC Yukon XL (1500, 2500): 1998-1999
- Chevrolet Tahoe / GMC Yukon: 1998-1999
- Cadillac Escalade: 1999
- Chevrolet Astro / GMC Safari: 1998
- Chevrolet S10 / GMC Sonoma: 1998 (4.3L)
- Chevrolet Blazer / GMC Jimmy: 1998 (4.3L)
- Oldsmobile Bravada: 1998 (4.3L)
- Isuzu Hombre: 1998 (4.3L)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations your specific vehicle requires. This ensures correct engine performance, transmission shifting, and compatibility with your van’s options, making the installation process much smoother.
Is this part difficult to install myself?
No, this is a very DIY-friendly repair. The module is typically easy to access in the engine bay. The main task after the physical swap is a simple security relearn procedure, which does not require special tools. We provide instructions to guide you.
What is a security relearn procedure?
It’s a simple process that syncs the new PCM with your vehicle’s anti-theft system. Without it, the vehicle will not start. The procedure usually involves leaving the key in the ‘ON’ position for about 10-15 minutes, a few times. It’s a necessary step for these GM vehicles.
The part is listed as used. Is it reliable?
Yes. Each module is sourced from a salvaged vehicle and thoroughly inspected and tested to ensure it is fully functional. We then flash it with the latest GM software for your VIN, providing a reliable and cost-effective alternative to a new dealership part.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both the engine and the transmission. If your shifting issues are caused by faulty electronic signals from a bad PCM, this replacement will resolve them. However, it will not fix internal mechanical problems with the transmission itself.