Restore Peak Performance to Your GM Truck or Van
Is your GMC Sierra, Chevy Silverado, or Express van running rough, shifting erratically, or failing to start? 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 failed emissions tests to a complete no-start condition. This replacement PCM is the definitive solution to restore your vehicle’s factory performance and reliability.
This isn’t just a generic, off-the-shelf part. We provide a fully programmed module specific to your vehicle. Upon purchase, you will provide us with your Vehicle Identification Number (VIN), and our technicians will flash the unit with the latest, most stable software updates directly from GM. This critical step ensures seamless communication between the engine, transmission, and other onboard systems, eliminating the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
I once had a 2000 Chevy Express van towed in with a classic ‘no communication with PCM’ code. The owner had already replaced the fuel pump and crank sensor, chasing what he thought were simple component failures. After confirming power and ground to the module, we suspected the PCM itself. A quick check of the main ground wire on the engine block revealed it was corroded and loose. After cleaning and tightening that single connection, the original PCM came back to life. Before you condemn your module, always double-check the main power and ground connections at the PCM and on the engine block. It can save you hundreds of dollars and a lot of headaches.
Diagnosing a Failing 1999-2000 GMC 2500 PCM
The PCM in these GMT400 and early GMT800 platform vehicles is a robust unit, but age and environmental factors can lead to internal component failure. If you’re experiencing any of the following symptoms, your PCM is a likely culprit. A proper diagnosis is key, but these signs point directly to a failing engine computer.
Common Symptoms of a Bad PCM
- ✔ Check Engine Light is on with various communication or sensor-related trouble codes (e.g., P0600, P0605).
- ✔ Engine cranks but will not start, or starts and immediately stalls.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Misfires or rough idling that can’t be traced to spark plugs, wires, or coils.
- ✔ Intermittent stalling for no apparent reason.
- ✔ Failure to pass an emissions or smog test.
This direct-replacement Powertrain Control Module is engineered to solve these problems. By providing us with your VIN, you receive a unit that is ready for installation right out of the box. It restores the precise fuel delivery, ignition timing, and transmission shift points your vehicle was designed with. This module is a reliable and cost-effective way to get your truck or van back on the road and running smoothly.
This module is a direct replacement for part numbers: 16263494, 16265035, 8162634940, 218-11787, and 21811787. Please verify your part number before ordering to ensure compatibility.
Frequently Asked Questions
Do I need to have this PCM programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before shipping it to you. This makes it a plug-and-play installation, with no need for a dealer visit.
What information do you need from me?
After you place your order, we will need the 17-digit Vehicle Identification Number (VIN) from your vehicle. This is typically found on your driver’s side dashboard (visible through the windshield) or on the door jamb sticker.
Is any other procedure required after installation?
In most cases, no further action is needed. However, some GM vehicles of this era may require a security relearn procedure (often called a CASE relearn or Passlock relearn) to sync the new PCM with the anti-theft system. This is a simple procedure that can typically be done without special tools and instructions can be easily found online.
Where is the PCM located on my vehicle?
The location varies slightly. On most pickups like the GMC 2500, it’s in the engine compartment on the driver’s side, near the fender. On vans like the Express or Savana, it’s typically in the rear of the engine compartment on the driver’s side. On S-series trucks and SUVs, it’s often on the passenger side firewall.
Will this fix my transmission shifting problems?
If the shifting problems are caused by faulty electronic signals from the PCM, then yes, this will resolve them. The PCM controls transmission line pressure and shift solenoids, so a failing module is a very common cause of poor shifting performance.