Restore Peak Performance to Your GM Van or Truck
Is your 1999-2002 GMC Savana 1500 van running rough, stalling unexpectedly, or throwing confusing check engine light codes? As a technician with over two decades of experience, I’ve seen these symptoms countless times. The culprit is often a failing Powertrain Control Module (PCM), the central computer of your vehicle’s engine. A faulty PCM can wreak havoc on everything from fuel economy and transmission shifting to basic starting and running. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded. Don’t let a bad module dictate your vehicle’s performance.
This replacement PCM, part number 16263494, is the definitive solution. We take the guesswork and dealer-level expense out of the equation. Before we ship, we flash the module with the latest official GM software updates, specifically programmed to your vehicle’s unique Vehicle Identification Number (VIN). This ensures seamless communication with all other onboard systems, restoring the precise factory-intended operation. This is the same process a dealership would perform, but delivered directly to your door, ready for installation.
A Technician’s Notebook: The Intermittent No-Start
I remember a 2001 Express work van that came into my shop with a maddening problem. It would start and run perfectly for weeks, then suddenly refuse to start. No crank, no click, nothing. The owner had already replaced the battery and starter. After checking all the basics, I hooked up my high-end scanner and noticed intermittent communication loss with the PCM. On these GM vans, heat soak and vibrations in the engine compartment can, over many years, cause microscopic cracks in the PCM’s circuit board. This is why a simple code scan doesn’t always tell the whole story. We installed a VIN-programmed 1999-2002 Savana 1500 PCM, and the van never had the issue again. It’s a classic failure mode for these reliable but aging workhorses.
Common Signs of a Failing Powertrain Control Module
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Your vehicle fails to start or experiences intermittent starting problems.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ The engine stalls, stumbles, or runs rough for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass state emissions testing.
Straightforward PCM Installation Guide
Installing your new PCM is a manageable job for a confident DIYer. Follow these steps carefully to ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On most Savana/Express vans, the PCM is located in the engine compartment, on the left (driver’s) side, often near the rear. On some trucks or other models, it may be under the battery tray or on a fender well. Consult your vehicle’s service manual for the exact location.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs; do not force them. Inspect the connectors for any corrosion or damage.
- Remove the Old PCM: Unbolt the old module from its mounting bracket. Keep the hardware as you will need it for the new unit.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- Security Relearn (If Needed): In many cases, the vehicle will start and run immediately. However, some GM vehicles require a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the anti-theft system to recognize the new PCM.
Confirmed Vehicle Fitment List
This module is a direct replacement for part number 16263494 and is compatible with the following part numbers: 16265035, 8162634940, 218-11787, 21811787. It fits a wide range of GM trucks and vans. Please verify your vehicle is on this list. The ID number 16263494 is the key identifier for many applications.
CHEVROLET BLAZER S10 98-00
CHEVROLET 1500/2500/3500 PICKUP 99-00
CHEVROLET EXPRESS 1500/2500/3500 VAN 99-02
CHEVROLET S10/SONOMA 98-00
CHEVROLET SILVERADO 1500 99-00 (6 cyl)
CHEVROLET SUBURBAN 1500/2500 99
CHEVROLET TAHOE 99-00 (Classic Style)
CADILLAC ESCALADE 99-00
GMC ENVOY 98-00
GMC JIMMY S15 98-00
GMC 1500/2500/3500 PICKUP 99-00
GMC SAFARI 99-01
GMC SAVANA 1500/2500/3500 VAN 99-02
GMC SIERRA 1500 PICKUP 99-00 (6 cyl)
GMC YUKON 99-00 (incl. Denali)
ISUZU HOMBRE 98-00 (4.3L)
OLDSMOBILE BRAVADA 98-00
How do I provide my VIN for programming?
After you complete your purchase, simply reply to your order confirmation email with your 17-digit VIN, or send it to us through the contact form on our website with your order number. We cannot ship your module until we receive this information.
Is this module ready to install out of the box?
Yes. Once we program it with your vehicle’s VIN, it is ready to be installed. In some cases, a simple, key-on/key-off security relearn procedure may be required, which does not need any special tools.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like codes P0601-P0606), this part will resolve the issue. However, if the light is on for another reason (e.g., a bad oxygen sensor), you will still need to fix that separate problem.
What if my original part number is different?
This module directly replaces several part numbers, including 16265035 and 8162634940. As long as your vehicle, year, and engine are on our compatibility list, this module will function correctly once programmed to your VIN.
Is this a difficult part for a DIYer to replace?
For most of the vehicles listed, this is a straightforward replacement. It typically involves disconnecting the battery, unplugging a few harness connectors, and unbolting the module. No advanced mechanical skills are required, but you should be comfortable working in your engine bay.