Restore Peak Performance to Your GM Workhorse
As a technician with over two decades of experience, I know that when a work van like your 1999-2002 Chevrolet Express 2500 goes down, it’s more than an inconvenience—it’s a hit to your bottom line. Unexplained stalling, a persistent check engine light, or a complete no-start condition can often be traced back to a failing Powertrain Control Module (PCM). This isn’t just a part; it’s the brain of your vehicle’s engine and transmission, and when it falters, the entire vehicle suffers. This replacement Express 2500 Van PCM is the definitive solution to get your reliable vehicle back in service, fast.
We take the guesswork and hassle out of the repair. Unlike a generic module from a parts store, this unit is professionally programmed with the latest GM software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) after your purchase. This critical step ensures that all factory parameters for fuel delivery, ignition timing, and transmission shifting are perfectly calibrated, restoring the smooth operation and efficiency you depend on. This is the same process a dealership would perform, but without the high cost and scheduling delays.
Case Study: A Tricky Diagnosis
I remember a fleet customer with a 2001 Savana 2500—a sister vehicle to the Express—that had a baffling issue. The van would run perfectly for 20-30 minutes and then suddenly stall, refusing to restart until it cooled down completely. The driver was stranded multiple times. We checked fuel pressure, swapped sensors, and chased wiring, but everything tested fine. On a hunch, I used a heat gun on the original PCM, and within minutes, the engine sputtered and died. The internal circuits were failing under thermal stress. We installed one of our VIN-programmed modules, and the van has been a reliable part of their fleet ever since. This experience underscores how a failing PCM can mimic many other problems, making a quality replacement the key to a lasting repair.
Is Your Van Exhibiting These Telltale PCM Failure Signs?
A faulty PCM can create a wide range of frustrating and often intermittent symptoms. If you’re experiencing any of the following, a failing computer is a likely culprit:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but will not start.
- ✔ Unexplained stalling, especially after the engine has warmed up.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Communication errors with your scan tool.
- ✔ Other modules on the vehicle setting ‘No Communication with PCM’ codes.
A Straightforward Guide to Installation
Replacing the Express 2500 Van PCM is a job most DIYers or any professional mechanic can handle with basic tools. Our VIN programming makes this a true plug-and-play repair.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On most Express and Savana vans, the PCM is located in the engine compartment, on the left-hand (driver’s) side, near the rear.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old PCM. Inspect the terminals for any corrosion or damage.
- Swap the Modules: Unbolt the old PCM from its mounting bracket and install the new module in its place.
- Reconnect and Secure: Firmly plug the electrical harnesses into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: Your vehicle is equipped with a Passlock/VATS security system. You will need to perform a simple 10-minute or 30-minute relearn procedure so the new PCM recognizes your key. This procedure requires no special tools and instructions are readily available online or in your service manual.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit a wide range of GM trucks and vans from the era. Please verify your vehicle is on the list below to ensure proper fitment.
Frequently Asked Questions
Do I need to do anything after I buy it?
Yes. After your purchase, you must send us your 17-digit VIN. We cannot program and ship the module without it. This ensures it works correctly with your vehicle’s specific options.
Is this a plug-and-play part?
Almost. Because we program it to your VIN, you will NOT need a dealer or high-end scan tool for programming. However, you will need to perform a simple security relearn procedure with your key, which takes about 30 minutes and requires no tools.
Will this fix my transmission shifting problems?
If the shifting problems are caused by a faulty PCM, then yes. The PCM controls shift points and line pressure based on sensor inputs. A failing module is a very common cause of erratic shifting in these GM vehicles.
What if my original part number isn’t 16265035?
This module is a direct replacement for several part numbers, including 16263494, 8162634940, and others listed. As long as your vehicle is on the compatibility list, this module will function correctly once programmed to your VIN.
Is a core charge required?
This listing does not require a core charge. You can keep your old module, though we always recommend recycling old electronics responsibly.