Restore Peak Performance to Your GM Truck or Van
Is your trusty GMC Sierra, Chevy Silverado, or Express van suddenly running rough, stalling, or showing a persistent Check Engine Light? Before you start throwing parts at it, consider the brain of the operation: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless vehicles with perplexing issues—poor fuel economy, erratic shifting, and no-start conditions—that all traced back to a failing PCM. This isn’t just a part; it’s the central command for your engine’s performance and efficiency.
This replacement 1999-2000 Sierra 1500 PCM is your direct-fit, reliable solution. The biggest headache with replacing a PCM is the need for expensive, dealer-only programming. We eliminate that completely. When you order, you simply provide us with your vehicle’s VIN, and we will program the module with the very latest GM factory software updates. This ensures it communicates flawlessly with your truck’s specific systems, often correcting issues that the original software didn’t. You get a component that’s ready for installation right out of the box, saving you time, money, and a trip to the dealership.
A Technician’s Notebook: The Case of the Confused Express Van
A local delivery business brought in their 2001 Express 2500 van. The complaint was intermittent stalling at stoplights and a transmission that seemed to shift harshly for no reason. They had already replaced the fuel filter and a couple of sensors with no luck. The scan tool showed a generic communication error code (U0100) and a processor fault (P0606) that would come and go. After verifying the wiring and grounds were solid—a critical first step—I suspected the PCM. Instead of a costly new unit from the dealer, we opted for a professionally sourced, VIN-programmed module like this one. After a 15-minute swap, the van ran perfectly. The pre-loaded software corrected the communication glitches, and the owner was back on the road making deliveries the same afternoon. It’s a perfect example of how the right part, correctly prepared, can solve even the most frustrating problems.
Common Signs of a Failing PCM
- ✔ Your vehicle fails to start or is very difficult to start.
- ✔ The Check Engine Light is illuminated, especially with codes like P0601, P0602, P0606, or U-series communication codes.
- ✔ A noticeable drop in fuel efficiency.
- ✔ The engine stalls, stumbles, or misfires for no apparent reason.
- ✔ Automatic transmission shifts are harsh, late, or erratic.
- ✔ The engine continues to run after the key is turned off.
A Straightforward Guide to Installation
Replacing your 1999-2000 Sierra 1500 PCM is a job most DIYers can handle with basic tools. The location can vary slightly depending on your exact model (e.g., under the battery on a Sierra/Silverado, in the engine compartment on an Express van), but the process is generally the same.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for the system capacitors to discharge.
- Locate the PCM: Find the module in your engine bay. It’s a metal box with several large electrical connectors. On most 1999-2000 Sierra and Silverado models, it is located on the driver’s side, under or near the battery tray.
- Disconnect the Connectors: Carefully unlatch and remove all electrical harnesses from the old PCM. These connectors often have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New Module: Bolt the new, pre-programmed PCM into place. Reconnect all the electrical harnesses, ensuring they click securely into place.
- Reconnect the Battery: Reattach the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves cycling the key. Consult your owner’s manual for specific instructions if needed.
Will This Fit My Vehicle?
This module is a direct replacement for service number 16263494 and part number 218-11787. It is guaranteed to fit a wide range of GM trucks and vans. Please verify your vehicle is on the list below. Providing your VIN during checkout is crucial to ensure we send you a perfectly matched and programmed unit.
– ASTRO VAN (99-01)
– BLAZER/JIMMY S-Series (98-00)
– BRAVADA (98-00)
– CADILLAC ESCALADE (99-00)
– CHEVROLET/GMC PICKUPS 1500/2500/3500 (99-00)
– ENVOY (98-00)
– EXPRESS/SAVANA VANS 1500/2500/3500 (99-02)
– ISUZU HOMBRE (98-00)
– S10/SONOMA PICKUP (98-00)
– SAFARI VAN (99-01)
– SILVERADO/SIERRA 1500 (99-00)
– SUBURBAN (99)
– TAHOE/YUKON (99-00)
Note: Fitment can depend on specific options like engine size (4.3L, 5.0L, 5.7L) and build dates. Matching your part number or providing your VIN is the best way to guarantee compatibility.
Frequently Asked Questions
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to access the specific factory calibration file for your truck. We use it to program the PCM with the latest GM software, ensuring it works perfectly with your engine, transmission, and options package.
Is any additional programming required after installation?
No. This module arrives ready to install. In most cases, you will not need to perform any additional programming. Some vehicles may require a simple security relearn procedure (often just cycling the key), which does not require special tools.
What’s the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM (Engine Control Module) typically just controls engine functions. A PCM (Powertrain Control Module) is more integrated and controls both the engine and the transmission, which is common in these GM vehicles.
How do I find the part number on my existing module?
Your original module will have a sticker on it with a large Service Number (SERV. NO.), which is typically 8 digits long. Matching this number (e.g., 16263494) is a great way to confirm you’re ordering the correct part.
Will this fix my poor gas mileage?
If your poor fuel economy is caused by a faulty PCM that is not correctly managing the air/fuel mixture or ignition timing, then yes, replacing it with this properly programmed module can restore your vehicle’s original MPG.