Is Your GM Truck or Van Running Rough?
If your Chevrolet Express, GMC Savana, or other compatible GM vehicle from the 1999-2002 era is suffering from mysterious performance issues, a failing Powertrain Control Module (PCM) is a likely culprit. As the central computer for your engine and transmission, a faulty PCM can cause a cascade of problems, from a simple check engine light to a frustrating no-start condition. This module is the direct-fit, reliable solution to get your workhorse back on the road, operating at peak efficiency.
From the Diagnostic Bay
We had a 2001 Savana 2500 in the shop that was driving the owner crazy. It would randomly stall at stoplights, but only when warm. There were no consistent trouble codes, just a generic P0300 random misfire that would pop up occasionally. We checked fuel pressure, spark, and vacuum linesโall were perfect. After hours of chasing ghosts, we hooked up a scope to the injector control signals from the PCM. Sure enough, as the engine bay heated up, the signal to injector #3 would drop out intermittently. The PCM’s internal driver was failing under heat. Swapping in a VIN-programmed module like this one solved the problem instantly. It’s a classic example of how a failing PCM can create symptoms that mimic other, more common failures.
The Brains of Your Operation: A VIN-Programmed Solution
Don’t settle for a generic, off-the-shelf module that requires expensive dealer programming. We take the guesswork and extra cost out of the equation. When you purchase this PCM, you provide us with your vehicle’s Vehicle Identification Number (VIN). Our technicians then flash the module with the latest, most stable GM-certified software specific to your exact vehicle configuration. This ensures seamless communication between all vehicle systems, proper transmission shift points, accurate fuel delivery, and correct emissions control from the moment you install it.
Common Symptoms of a Failing GM PCM
- โ Persistent Check Engine Light (CEL) with various codes, or no codes at all.
- โ Engine stalling, stumbling, or hesitating during acceleration.
- โ Rough or erratic idling.
- โ A noticeable decrease in fuel economy.
- โ Harsh or incorrect automatic transmission shifting.
- โ Complete no-start or intermittent starting issues.
- โ Failure to communicate with a diagnostic scan tool.
Why Choose Our Programmed 1999-2002 Express 3500 PCM?
This isn’t just a replacement part; it’s a comprehensive solution. By installing our precisely programmed 1999-2002 Express 3500 PCM, you are restoring the core logic of your vehicle’s powertrain. This module is compatible with a wide range of GM trucks and vans equipped with gasoline engines, including the venerable 4.3L, 5.0L, and 5.7L Vortec powerplants. It directly replaces OEM part numbers like 16263494 and 16265035, guaranteeing a perfect fit and function.
Installation is straightforward for any DIY mechanic or professional technician. After disconnecting the battery, simply unbolt the old module, disconnect the wiring harnesses, and install the new one. In most cases, a simple security relearn procedure (often called the Passlock or VATS relearn) is all that’s needed to get your vehicle running again. This procedure typically involves a sequence of key turns and can be done in your driveway without special tools.
By ordering this pre-programmed 1999-2002 Express 3500 PCM, you are not just buying a part. You are investing in reliability, restored performance, and peace of mind. Eliminate the frustrating diagnostic guesswork and get your truck or van back to work.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It controls all aspects of engine and transmission operation, including fuel injection, ignition timing, emissions systems, and automatic transmission shifting, to ensure optimal performance and efficiency.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) contains critical information about your vehicle’s specific options, engine, transmission, and emissions equipment. We use the VIN to load the exact GM-approved software for your vehicle, ensuring a perfect match and proper function without needing a trip to the dealer.
Is this part difficult to install?
Installation is generally simple. It involves disconnecting the battery, unplugging the electrical connectors, and unbolting the old module. The new one bolts in its place. The most common additional step is a security relearn procedure, which can usually be done by the owner with simple instructions.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this will resolve the issue. However, the check engine light can be triggered by hundreds of potential problems. It’s crucial to have your vehicle properly diagnosed to confirm the PCM is the root cause of the fault codes.
What is the security relearn procedure?
This is a process that syncs the new PCM with your vehicle’s anti-theft system. It typically involves turning the ignition key to the ‘ON’ position for about 10-15 minutes, then off, and repeating the cycle two more times. This allows the components to recognize each other. Instructions are widely available online for your specific model.
Is this compatible with my Chevy S10 or GMC Jimmy?
Yes, this PCM is compatible with a wide range of GM vehicles from this era that use part number 16263494, including the S10/Sonoma, Blazer/Jimmy, and many full-size trucks and vans. Please check the detailed fitment list on this page to confirm compatibility with your specific model and year.