Restore Peak Performance to Your Workhorse Truck
As a technician with over two decades of experience, I’ve seen my fair share of hardworking trucks sidelined by frustrating electrical gremlins. If your 1999 or 2000 Chevrolet 3500 Pickup is suddenly stalling, shifting erratically, or throwing a check engine light that won’t go away, the problem is often the very brain of your engine: the Powertrain Control Module (PCM). A failing PCM can cause a cascade of issues that can make your reliable truck feel unpredictable and unsafe. Don’t let a faulty computer put you out of commission. This is the direct, dependable solution you need.
This isn’t just a replacement part; it’s a restoration of your truck’s original operating parameters. We take the guesswork out of the repair by pre-programming this PCM specifically for your vehicle using your VIN. This ensures that all factory settings for the engine, transmission, and emissions systems are perfectly matched. We also load the latest GM software updates, which can resolve issues you didn’t even know were software-related. This is the most effective way to solve complex drivability problems and ensure your truck runs as it should.
A Technician’s Notebook
I remember a 2000 Chevy 3500 tow rig that came into my shop. The owner was at his wit’s end. The truck would run fine for 20 minutes, then suddenly die and refuse to restart for an hour. No codes, no obvious faults. After checking fuel pressure and spark, I suspected the PCM. On these trucks, the module is in the engine bay where it gets baked by heat. I used a heat gun on the old PCM, and sure enough, the truck stalled. A new, properly programmed module like this one had him back on the road, pulling trailers without a worry. Heat-soak failure is a classic symptom for these units.
Is Your Truck Exhibiting These PCM Failure Signs?
A failing computer can manifest in many ways. If you’re experiencing any of the following, a faulty PCM is a likely culprit. Confirming your diagnosis is key, and these symptoms are major red flags I look for in the bay.
- ✔ Check Engine Light is on with codes like P0601, P0604, or P0606.
- ✔ Engine stalling or randomly shutting off while driving.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Vehicle won’t start, but the battery and starter are good.
- ✔ Noticeable decrease in fuel economy.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Misfires or rough idle that can’t be traced to plugs, wires, or coils.
A Straightforward Guide to Installation
Replacing the PCM on your 1999-2000 Chevrolet 3500 Pickup is a job most DIYers can handle with basic tools. The key is patience and following the steps carefully. This module is typically located in the left-hand (driver’s side) front of the engine compartment.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: Find the existing module in the engine bay. It’s a metal box with several large multi-pin electrical connectors.
- Disconnect the Harnesses: Carefully unclip and remove all electrical connectors from the old PCM. Be gentle, as the plastic clips can become brittle over time.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket.
- Reconnect Everything: Firmly plug all electrical harnesses back into the new module. Ensure they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure (often called a Passlock relearn) so the vehicle recognizes the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Instructions are readily available online for your specific model.
Verified Vehicle Compatibility
This module is a direct replacement for original part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following gasoline-engine GM trucks and vans. Please verify your vehicle is on the list below.
CHEVROLET 2500 PICKUP 99-00 (gasoline)
CHEVROLET 1500 PICKUP 99 (5.0L, 5.7L)
SILVERADO 1500 PICKUP 99-00 (4.3L V6)
TAHOE 99-00 (Classic style)
SUBURBAN 1500/2500 99 (gasoline)
GMC 3500 PICKUP 99-00 (gasoline)
GMC 2500 PICKUP 99-00 (gasoline)
GMC 1500 PICKUP 99 (5.0L, 5.7L)
SIERRA 1500 PICKUP 99-00 (4.3L V6)
YUKON 99-00 (incl. Denali)
CADILLAC ESCALADE 99-00
CHEVROLET EXPRESS VAN 1500/2500/3500 99-02 (gasoline)
GMC SAVANA VAN 1500/2500/3500 99-02 (gasoline)
CHEVROLET ASTRO VAN 99-01
GMC SAFARI VAN 99-01
CHEVROLET S10 / GMC SONOMA 98-00 (4.3L)
CHEVROLET BLAZER / GMC JIMMY 98-00 (4.3L)
OLDSMOBILE BRAVADA 98-00 (4.3L)
GMC ENVOY 98-00
ISUZU HOMBRE 98-00 (4.3L)
Frequently Asked Questions
Do I need to do anything after I purchase?
Yes. After your purchase, you must send us your vehicle’s 17-digit VIN. We cannot program and ship your module without it. This ensures a perfect match for your truck’s specific configuration.
Is this module difficult to install?
No, installation is straightforward for most DIY mechanics. It involves disconnecting the battery, swapping the modules, and performing a simple key-on security relearn procedure. No special tools are required.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls engine performance and transmission shift points. If the module is faulty, it can cause harsh shifting, delayed engagement, or failure to shift. This programmed module restores those critical functions.
What does ‘programmed with the newest updates’ mean?
Over the life of a vehicle, manufacturers like GM release software updates to fix bugs, improve drivability, and enhance performance. We load the latest official GM calibration for your VIN, ensuring your vehicle benefits from all available factory improvements.
Is a core charge required?
No, you do not need to return your old, faulty module. This purchase does not require a core charge, saving you time and hassle.