If you’re dealing with a frustrating Check Engine Light, erratic engine behavior, or a no-start condition on your 1999-2000 Silverado 1500, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty engine computer can cause a cascade of problems that are tough to pin down. This isn’t just a part; it’s the brain of your truck’s engine and transmission, and when it’s not working correctly, your entire vehicle suffers.
We’re offering a direct-fit replacement PCM that eliminates the guesswork and costly trips to the dealership. The biggest hurdle with replacing a PCM has always been the programming. We solve that for you. Simply provide your vehicle’s VIN at checkout, and my team will program this module with the latest GM factory software specific to your truck. This ensures that when it arrives, it’s ready for a straightforward installation, restoring the precise fuel delivery, spark timing, and transmission shift points your vehicle had when it was new.
From the Diagnostic Bay
I remember a 2000 GMC Sierra (which uses the same platform as the Silverado) that came into my shop. The owner had replaced three different sensors trying to fix a persistent rough idle and terrible gas mileage. His scanner wasn’t showing any specific sensor codes, just a generic internal controller error (P0606). After confirming the wiring was solid, we swapped in a pre-programmed PCM like this one. The idle smoothed out instantly, and a week later, he called back to say his fuel economy had improved by 4 MPG. It’s a classic case where chasing symptoms costs more time and money than addressing the root cause—the failing computer.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution for your 1999-2000 Silverado PCM issues:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes (DTCs) for internal module failure, like P0601, P0602, or P0606
- ✔ Unexplained drop in fuel economy
- ✔ Rough or unpredictable engine idling
- ✔ Engine stalling or cutting out while driving
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to pass an emissions test
- ✔ Complete no-start condition where the engine cranks but won’t fire
A Straightforward Guide to Installation
Installing your replacement 1999-2000 Silverado PCM is a job most DIYers can handle in their own driveway. For the Silverado/Sierra, the module is typically located in the engine bay on the driver’s side, under the battery tray.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system to fully discharge.
- Locate the Module: On most trucks, you’ll need to remove the battery to access the PCM mounted below it. On vans like the Express/Savana, it may be in the rear of the engine compartment.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs; be gentle to avoid breaking them. Inspect the connectors for any corrosion or damage.
- Remove Old PCM: Unbolt the old module from its mounting bracket and remove it from the vehicle.
- Install New PCM: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click. Reinstall and reconnect the battery, starting with the positive terminal, then the negative.
- Perform Security Relearn: After installation, you will need to perform a security relearn procedure (often called a CASE relearn) to sync the new PCM with your vehicle’s anti-theft system. This procedure typically involves a series of key cycles and can be found in your owner’s manual or online.
Verified Vehicle Compatibility
This module is a direct replacement for multiple part numbers, including 16263494, 16265035, and 8162634940. It fits a wide range of GM trucks, vans, and SUVs. While the primary application is the 1999-2000 Silverado PCM for 6-cylinder models, please check the comprehensive list below to confirm fitment for your specific vehicle.
- Chevrolet Silverado/GMC Sierra 1500 (99-00): 4.3L 6-Cylinder models
- Chevrolet/GMC C/K 1500, 2500, 3500 Pickups (99-00): Various gasoline engines, check ID 16263494
- Chevrolet Tahoe/GMC Yukon (99-00): Including classic style and Denali models
- Chevrolet Suburban 1500/2500 (99): Gasoline models with ID 16263494
- Chevrolet S10/GMC Sonoma (98-00): 4.3L V6 models
- Chevrolet Blazer/GMC Jimmy (98-00): 4.3L V6 models
- Chevrolet Astro/GMC Safari (99-01): 4.3L V6 models
- Chevrolet Express/GMC Savana Vans 1500, 2500, 3500 (99-02): Various gasoline models
- Oldsmobile Bravada (98-00): 4.3L V6 models
- Cadillac Escalade (99-00)
- Isuzu Hombre (98-00): 4.3L V6 models
Frequently Asked Questions
Do I need to do anything after I buy this?
Yes. After your purchase, you MUST send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive your VIN, as we need it to program the module specifically for your vehicle.
Is this a simple plug-and-play installation?
It’s very close. Because we pre-program it to your VIN, you will not need a dealership scan tool for programming. However, you will need to perform a security relearn procedure after installation, which involves a sequence of key turns to sync the module with your vehicle’s security system. This procedure is straightforward and can be done at home.
Will this fix my transmission problems?
If your transmission issues, like hard or late shifting, are caused by faulty signals from the PCM, then yes, this module will resolve them. The PCM controls both engine and transmission functions on these vehicles.
How do I find my original part number to verify a match?
Your original part number is printed on a sticker on the case of your current PCM. You can cross-reference it with the compatible numbers listed: 16263494, 16265035, 8162634940, and 218-11787.