Restore Peak Performance to Your GM Truck or Van
Is your trusty Chevrolet or GMC truck suffering from frustrating issues like a persistent check engine light, erratic engine behavior, or transmission problems? You’re not just dealing with a minor annoyance; you’re likely facing a failing Powertrain Control Module (PCM), the central computer of your vehicle. As a technician with over two decades of experience, I’ve seen firsthand how a faulty PCM can cause a cascade of problems that seem unrelated. This isn’t just a part; it’s the solution to getting your reliable workhorse back on the road, running as it should.
This replacement 1999 Suburban 2500 PCM is your direct path to a lasting repair. We take the biggest headache out of the process: programming. Simply provide us with your vehicle’s VIN after purchase, and our experts will flash this module with the latest, most stable software updates directly from GM. This ensures perfect compatibility and often corrects underlying factory bugs that your original module may have had. You get a component that is ready to install right out of the box, saving you a costly trip to the dealership and hours of diagnostic frustration.
Case Study: The Intermittent No-Start
I remember a 2000 Chevy Express van that came into my shop. The owner, a plumber, was losing business because his van would randomly refuse to start. No codes, no clear pattern. We checked the fuel pump, ignition system, and battery—all were fine. After hours of tracing wires, we hooked up a scope to the PCM’s injector driver circuits. We found that on hot days, the driver for cylinder 3 would intermittently fail, preventing the engine from firing. A replacement PCM, programmed to his VIN, solved the problem instantly. It’s often these internal, heat-related failures within the PCM that create the most elusive and frustrating symptoms.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution.
- ✔ Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module Read Only Memory (ROM) Error).
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A complete no-start condition where the engine cranks but won’t fire up.
- ✔ Noticeable decrease in fuel economy.
- ✔ Failure to communicate with a diagnostic scan tool.
Your Straightforward PCM Installation Guide
Installing your new 1999 Suburban 2500 PCM is a job most DIYers can handle in their own driveway. Follow these steps for a smooth installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the Module: On most trucks and SUVs like the Suburban or Tahoe, the PCM is located in the engine compartment, typically on the driver’s side fender well. On Express/Savana vans, it’s often in the LH rear of the engine compartment.
- Disconnect Connectors: Carefully unclip and remove the electrical wiring harnesses from the old PCM. The connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Unbolt and Remove: Remove the bolts or nuts holding the old PCM bracket in place and lift the module out of the vehicle.
- Install the New PCM: Place your new, pre-programmed module into the mounting bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: Some vehicles may require a simple security relearn procedure to sync the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s specific procedure if needed.
Verified Fitment For These GM Vehicles
This module is a direct replacement for a wide range of GM vehicles. It is compatible with part numbers 16263494, 16265035, 8162634940, and 21811787. Please verify your vehicle is on the list below. If your original module has ID 16263494, this is a confirmed match.
Fits various 1998-2002 Chevrolet, GMC, Cadillac, and Isuzu models including: Astro/Safari, Blazer/Jimmy, Bravada, Escalade, Express/Savana Vans (1500/2500/3500), S10/Sonoma, Hombre, Silverado/Sierra Pickups (1500/2500/3500), Suburban, Tahoe, and Yukon. This is the correct 1999 Suburban 2500 PCM for gasoline models.
Frequently Asked Questions
Do I need to get this programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before we ship it. It arrives ready for installation, saving you time and money.
How do I give you my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship the part until we receive this information.
What is the security relearn procedure?
For many GM vehicles of this era, it’s a simple process. After installation, turn the ignition key to the ‘ON’ position (without starting the engine) and leave it for 10-15 minutes. The ‘Security’ light should turn off. Turn the key off, wait a minute, and then the vehicle should start.
Where is the PCM located on my 1999 Suburban 2500?
On the 1999 Suburban 2500 with a gasoline engine, the PCM is located in the engine compartment on the driver’s side (LH) inner fender.
Will this fix my hard shifting transmission?
In many cases, yes. The PCM controls transmission line pressure and shift points. If the module is failing, it can cause erratic and harsh shifting. Replacing a faulty PCM often restores smooth transmission operation.