Restore Peak Performance to Your GM Truck or Van
Is your 1999-2000 GMC 3500, Chevy Silverado, or Express van running rough, shifting poorly, or showing a persistent check engine light? These are classic signs of a failing Powertrain Control Module (PCM), the central computer responsible for managing your vehicle’s engine and transmission. A faulty PCM can lead to a frustrating driving experience, poor fuel economy, and even prevent your vehicle from starting. This replacement module is the definitive solution to restore your vehicle’s original performance and reliability.
The Brains of Your Operation: Why a Healthy 1999-2000 GMC 3500 PCM is Crucial
The PCM in your GM vehicle is a sophisticated computer that processes data from dozens of sensors in real-time. It controls critical functions like fuel injection timing, spark advance, transmission shift points, and emissions systems. When it begins to fail, the signals it sends become erratic, causing a cascade of problems that can be difficult to diagnose. Instead of spending countless hours and dollars chasing individual sensor codes, addressing the root cause with a new PCM is often the most effective and efficient repair.
From the Diagnostic Bay
We had a 2000 Chevy Express 2500 work van come into the shop that had its owner completely stumped. The van would randomly stall at idle and had a nasty hesitation under acceleration. The check engine light was on, throwing codes for the MAP sensor and an O2 sensor. The owner had already replaced both sensors, but the problem persisted. After hooking up our professional scan tool, we noticed the live data stream from the PCM was freezing and dropping out intermittently. This pointed directly to an internal failure in the module. We installed a VIN-programmed PCM like this one, performed the security relearn, and the van ran perfectly. It’s a textbook example of how a failing computer can send you on a wild goose chase for other non-existent problems.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns with various codes.
- ✔ Your vehicle experiences rough idling, stalling, or is hard to start.
- ✔ A noticeable and unexplained drop in fuel mileage.
- ✔ Harsh, delayed, or erratic automatic transmission shifting.
- ✔ Engine misfires, stumbles, or hesitates during acceleration.
- ✔ A complete no-start condition where the engine cranks but will not fire up.
- ✔ Inability for a scan tool to communicate with the vehicle’s computer.
A True Plug-and-Play Solution
Don’t settle for a generic, unprogrammed module from a salvage yard that will cause more headaches. This PCM is professionally flashed with the latest official GM software updates specifically for your vehicle. By providing us with your Vehicle Identification Number (VIN) during checkout, we ensure the module arrives ready for installation. This critical programming step matches the PCM to your truck’s specific engine, transmission, and factory options, ensuring seamless integration and optimal performance right out of the box. For many vehicles on the extensive fitment list, this eliminates the need for expensive dealership programming.
This module is a direct replacement for multiple part numbers, including 16263494, 16265035, and 8162634940. It fits a wide range of popular GM models from the late 90s and early 2000s, including the Chevy Silverado, GMC Sierra, Tahoe, Yukon, S10, Blazer, Astro, Express, and Savana vans. Please verify your part number or consult the detailed fitment list to confirm compatibility.
Frequently Asked Questions
Why do you need my VIN to program the PCM?
Your vehicle’s VIN (Vehicle Identification Number) allows us to flash the PCM with the exact software and calibrations specific to your truck’s engine, transmission, tire size, and other factory-installed options. This ensures perfect compatibility and performance without requiring a trip to the dealer.
Is this a simple plug-and-play installation?
Yes, for most vehicles. Once programmed to your VIN, the module is ready to be installed. However, some GM vehicles of this era are equipped with a Passlock or VATS anti-theft system which may require a simple security relearn procedure after installation. This procedure can typically be done without special tools and instructions are readily available online.
Will this PCM fix my check engine light?
If the check engine light and associated trouble codes are being caused by a faulty PCM, then yes, this part will resolve the issue. It’s crucial to ensure that other components like sensors and wiring have been properly diagnosed first.
Where is the PCM located on my vehicle?
The location varies by model. On many trucks like the GMC 3500 and Chevy 2500, it’s in the engine compartment on the driver’s side. On vans like the Express and Savana, it’s often in the rear of the engine compartment. For S10/Blazer models, it’s typically on the passenger side firewall. Always disconnect the battery before removal or installation.
What is the difference between a PCM, ECM, and ECU?
The terms are often used interchangeably. ECM (Engine Control Module) typically just controls the engine. A PCM (Powertrain Control Module) controls both the engine and the transmission. ECU (Electronic Control Unit) is a more generic term. For this application, PCM is the most accurate description.