Is Your Work Van Suddenly Unreliable?
For a workhorse like your 1999-2002 Chevrolet Express 3500, reliability isn’t just a featureโit’s everything. When it starts acting up with baffling electrical gremlins, it costs you time and money. You might be experiencing a crank-no-start condition one day, and the next it runs fine. Or maybe the check engine light is on with a host of communication codes that don’t seem to point to a specific sensor, and the transmission is shifting harshly. These are classic signs that the brain of your vehicle, the Powertrain Control Module (PCM), is failing.
From the Shop Floor: A Real-World Diagnosis
“A customer’s 2001 Express 3500 came in last week with these exact symptoms. It was a fleet vehicle, and the driver reported it would randomly stall and refuse to restart for an hour. They had already replaced the battery and the crank sensor with no luck. When I hooked up my scan tool, I couldn’t communicate with the PCM. After checking the powers and grounds to the module connectors, I knew they were good. The final test was checking the 5-volt reference signal to the sensorsโit was gone. This confirmed the PCM’s internal voltage regulator had failed. It’s a textbook failure I’ve diagnosed on hundreds of these GM vans and trucks from this era.”
The Direct Solution: A VIN-Programmed PCM
Don’t keep throwing parts at the problem. This Powertrain Control Module is the definitive solution to restore your vehicle’s performance and dependability. The PCM is the central command unit, responsible for managing everything from fuel injector pulse width and ignition timing to transmission shift points. When it fails, the entire powertrain is compromised.
The biggest hurdle in replacing a PCM has always been the programming. This module solves that. We handle the complex part for you. When you order, simply provide us with your vehicle’s 17-digit VIN. Our technicians will then program the module with the latest official GM software calibration for your exact vehicle. This ensures all systems, including the crucial Vehicle Anti-Theft System (VATS/Passlock), function correctly right out of the box.
What This Means For You:
- โ No Dealer Visit Required: Save yourself the time, hassle, and high cost of having a dealership program a new module.
- โ Plug-and-Play Installation: Once you receive the module, the physical installation is straightforward. It arrives ready to be installed and started.
- โ Resolves Common Failure Points: This module is the answer for a wide array of frustrating issues.
Common Symptoms of a Failing GM PCM:
- โ Check Engine Light (CEL) is on with communication-related DTCs (U-codes)
- โ Engine cranks but will not start
- โ Intermittent stalling or rough idling
- โ Harsh or erratic transmission shifting
- โ Poor fuel economy
- โ No communication with a scan tool
- โ Loss of spark or injector pulse
Installation and Verification
For most of the compatible vans like the Express and Savana, you’ll find the PCM located in the engine compartment on the left-hand (driver’s) side, often near the rear. On trucks like the Silverado or S10, it can be under the battery tray or on the fender. Always disconnect the negative battery terminal before beginning work.
Important Note: After installation, some vehicles may require a Crankshaft Position System Variation Relearn procedure (often called a CASE relearn) to clear a P1336 trouble code and ensure optimal engine timing. This procedure can be performed with most professional-grade scan tools.
Guaranteed Compatibility
This module is a direct replacement for several part numbers, ensuring a perfect match for your vehicle. Please verify your original part number against this list or use the fitment chart below.
- โ Part Numbers: 16263494, 16265035, 8162634940, 218-11787, 21811787
This part is engineered to fit a wide range of GM trucks and vans. Please confirm your specific model and year in the compatibility list provided to ensure a perfect fit.