Restore Peak Performance to Your GM Truck or Van
If your dependable Chevrolet 3500 is suffering from frustrating issues like a persistent check engine light, erratic shifting, stalling, or a no-start condition, the problem often lies with a failing Powertrain Control Module (PCM). As the electronic brain of your vehicle, the PCM governs everything from fuel mixture and ignition timing to transmission operation. When it falters, the entire vehicle’s performance suffers. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded.
As a technician with over 20 years of hands-on diagnostic experience, I’ve traced hundreds of these exact symptoms back to a faulty PCM. This isn’t just a part; it’s the central command for your powertrain. We offer a direct, reliable solution: a high-quality replacement 1999-2000 Chevrolet 3500 PCM that comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We install the latest GM software updates, ensuring your engine and transmission operate exactly as the manufacturer intended. This eliminates the need for an expensive trip to the dealership for programming, saving you time and money.
A Technician’s Notebook: The Case of the Confusing Codes
I once had a 2000 GMC 3500 pickup in my bay that was driving the owner crazy. It had an intermittent no-start, would sometimes stall at stoplights, and threw a mix of communication and sensor codes that didn’t seem related. The owner had already replaced the crank sensor and a few others with no luck. After checking the wiring for the third time, I focused on the PCM. On these specific GM platforms, I’ve seen internal driver circuits for injectors or ignition coils fail due to years of heat cycles. This creates bizarre, intermittent symptoms that mimic sensor failures. We installed a correctly programmed PCM, and the truck fired up instantly and ran perfectly. It’s a classic example of how a failing ‘brain’ can send you chasing ghosts all over the engine bay.
Is Your Vehicle Showing These Signs of PCM Failure?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution, especially if you’re seeing related Diagnostic Trouble Codes (DTCs).
- ✔ Check Engine Light: Often with internal module codes like P0601 (Internal Control Module Memory Check Sum Error), P0604, P0605, or P0606 (PCM Processor Fault).
- ✔ Engine Performance Issues: Stalling, rough idling, hesitation on acceleration, or a noticeable drop in fuel economy.
- ✔ Starting Problems: The engine cranks but won’t start, or it starts intermittently.
- ✔ Erratic Transmission Shifting: Harsh shifts, delayed engagement, or getting stuck in one gear (limp mode).
- ✔ Failed Emissions Test: Inability to pass smog due to module-related faults.
A Straightforward Guide to Installation
This module is designed for a direct fit, and installation is a job most DIYers or any professional mechanic can handle. No complex programming is required on your end.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1999-2000 Chevrolet/GMC pickups, the PCM is located in the engine compartment on the driver’s side, often near the fender or firewall.
- Disconnect the Harnesses: Carefully unclip and remove the electrical wiring harnesses connected to the old module. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket, reconnect the wiring harnesses securely, and re-attach the negative battery terminal.
- Perform Security Relearn (If Needed): Some vehicles may require a simple security relearn procedure. Typically, this involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine. This allows the vehicle’s anti-theft system to sync with the new module.
Verified Vehicle Compatibility List
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following vehicles (please verify your specific options):
- Chevrolet/GMC 1500/2500/3500 Pickups (1999-2000): Gasoline engines. Includes Silverado, Sierra, and classic body styles.
- Chevrolet Express / GMC Savana Vans (1999-2002): Gasoline engines.
- Chevrolet Tahoe / GMC Yukon (1999-2000): Including classic styles and Denali.
- Cadillac Escalade (1999-2000)
- Chevrolet Astro / GMC Safari (1999-2001)
- Chevrolet S10 / GMC Sonoma / Isuzu Hombre (1998-2000): 4.3L V6 engines.
- Chevrolet Blazer / GMC Jimmy / Oldsmobile Bravada / GMC Envoy (1998-2000)
Note: Some 1998 and 2001-2002 models require matching the ID number 16263494. Please check your original part to confirm.
Frequently Asked Questions
Do I need to get this PCM programmed by a dealer?
No. We handle all the programming for you before we ship the part. Simply provide your vehicle’s VIN during checkout, and it will arrive ready to install with the latest GM software.
What is a VIN and where do I find it?
The VIN is your 17-digit Vehicle Identification Number. It’s like a fingerprint for your truck. You can find it on your vehicle’s registration, insurance card, or on a small plate on the driver’s side of the dashboard, visible through the windshield.
Is this a guaranteed fix for my check engine light?
If the check engine light is caused by an internal failure of the PCM (like code P0601), then yes, this module will resolve the issue. However, if the light is on due to a faulty sensor or other component, that part will still need to be addressed.
What is the security relearn procedure?
It’s a simple process to sync the new PCM with your vehicle’s anti-theft system. After installation, you’ll typically turn the key to the ‘ON’ position (without starting) for 10-12 minutes, then ‘OFF’ for 30 seconds. Repeat this cycle three times, and the vehicle should then start and run normally.
How do I know if this is the right part for my truck?
This part replaces several original part numbers, including 16263494 and 8162634940. The best way to be certain is to check the part number on your existing module or use our detailed compatibility list. When in doubt, feel free to contact us with your VIN.