Restore Peak Performance to Your GM Vehicle
Is your 1999-2001 GMC Safari or other GM truck/van running rough, stalling unexpectedly, or showing a persistent Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the electronic brain of your vehicle. A faulty PCM can cause a cascade of frustrating issues, from poor fuel economy and erratic shifting to a complete no-start condition. This isn’t just an annoyance; it’s a reliability issue that can leave you stranded. This replacement PCM, part number 16263494, is the definitive solution to restore your vehicle’s factory operation and your peace of mind.
We take the guesswork and hassle out of the repair. Unlike a generic module from a parts store, each unit we ship is meticulously programmed with the latest official GM software updates, tailored specifically to your vehicle’s VIN. This ensures seamless communication between the engine, transmission, and other onboard systems. By providing your VIN at checkout, you receive a module that is truly ready for installation, eliminating the need for an expensive trip to the dealership for programming.
Common Signs of a Failing PCM
If you’re experiencing any of the following, a faulty module could be the culprit. I’ve seen these symptoms countless times in the shop, often after customers have already replaced other parts without success.
- ✔ Persistent Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes (DTCs) related to internal module failure, such as P0601, P0602, or P0606
- ✔ Unexplained engine stalling or stuttering
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Noticeable decrease in fuel efficiency
- ✔ Engine cranks but refuses to start
- ✔ Failure to pass an emissions inspection
A Technician’s Notebook: The Van That Wouldn’t Communicate
A customer brought in a 2000 Savana van that had multiple shops stumped. It had intermittent stalling and a whole array of communication codes (U-codes) on the scanner. They had replaced the fuel pump and a few sensors, but the problem always returned. After confirming good power and ground at the PCM connectors, I suspected the module itself was failing internally. The intermittent nature of the fault was classic PCM behavior. We installed a VIN-programmed module, performed the security relearn, and the van ran perfectly. The customer was thrilled to finally have a reliable work vehicle again. It’s a textbook example of how a failing 1999-2001 GMC Safari PCM can mimic other component failures.
DIY Installation: A Straightforward Guide
Replacing the PCM is a manageable job for a DIY enthusiast. Follow these steps for a smooth installation. In most of these vehicles, the module is located in the engine bay, often near the battery.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most Safari and Astro vans, it’s on the driver’s side of the engine compartment, near the battery. On pickups and other models, it may be on the driver’s side fender well.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old module. These connectors have locking tabs, so be gentle to avoid damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click firmly into place. Reconnect the negative battery terminal.
- Perform Security Relearn: Your vehicle’s anti-theft system may need to be relearned to the new PCM. This procedure is simple and typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times before starting the engine. Instructions for this can be easily found online for your specific model.
Will This Fit My Vehicle?
This module is a direct replacement for part number 16263494 and is also compatible with part numbers 16265035, 8162634940, 218-11787, and 21811787. It fits a wide range of GM trucks and vans. Please verify your vehicle from the list below:
CHEVROLET & GMC VANS (Express/Savana 1500/2500/3500) 1999-2002
CHEVROLET ASTRO & GMC SAFARI 1999-2001
CHEVROLET S10 / GMC SONOMA 1998-2000
CHEVROLET BLAZER / GMC JIMMY / OLDSMOBILE BRAVADA 1998-2000
CADILLAC ESCALADE 1999-2000
CHEVROLET TAHOE / GMC YUKON 1999-2000
ISUZU HOMBRE (4.3L) 1998-2000
Note: Please match your part number or consult the detailed list to ensure perfect fitment. A correct 1999-2001 GMC Safari PCM is critical for proper function.
Frequently Asked Questions
Do I need to do any programming myself?
No. We program the module to your vehicle’s VIN before shipping. The only step you may need to perform is a simple key-cycle security relearn procedure, which requires no special tools.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to load the exact, correct software calibration from GM for your specific engine, transmission, and emissions equipment. This guarantees compatibility and optimal performance.
Is this a new or used part?
This is a high-quality, inspected, and tested replacement part that has been prepared for service and programmed with the latest software for your vehicle.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls transmission shift points and line pressure. If the module is failing, it can directly cause poor shifting, and replacing it is often the correct fix.
What if my part number is slightly different?
This module replaces several part numbers, including 16265035 and 8162634940. As long as your vehicle is on the compatibility list and your original module is one of the listed compatible numbers, this part will work for you.