Is Your Workhorse Van Suddenly Unreliable?
As a technician with over two decades of experience, I know that when a work van like your 2003 Express 3500 goes down, it’s not just an inconvenienceโit’s a hit to your bottom line. You’re likely experiencing a frustrating set of symptoms that seem to come out of nowhere: the engine might stall at a stoplight, the transmission shifts erratically, or the check engine light is on with a list of confusing codes. These are classic signs that the brain of your vehicle, the Powertrain Control Module (PCM), is failing.
The PCM is the central command center for your engine and transmission. When it starts to malfunction due to age, heat cycles, or internal component failure, it can cause chaos throughout your vehicle’s systems. You need a solution that is reliable, fast, and doesn’t require an expensive trip to the dealership for programming. This is that solution.
The Direct-Fit Solution: A Pre-Programmed 2003 Express 3500 PCM
This Powertrain Control Module (part number 88864822) is the definitive answer to your vehicle’s electronic issues. We take the guesswork and hassle out of the repair. Before this module ever leaves our facility, we flash it with the latest GM-certified software, specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN). This ensures perfect communication between the module and all related components, restoring the performance and reliability you depend on.
Expert Pro Tip: Check Your Grounds Before You Swap!
Over the years, I’ve seen countless PCMs get replaced when the real culprit was a simple, overlooked ground connection. On these GM vans and trucks, the PCM case itself often acts as a critical ground path. Before you install your new module, take a wire brush and thoroughly clean the metal mounting bracket and the mounting points on the vehicle’s body. A clean, tight connection is essential for the PCM to function correctly and can prevent a host of phantom electrical issues. It’s a five-minute check that can save you hours of diagnostic headaches.
Symptoms of a Failing PCM This Part Corrects:
- โ Unexplained Check Engine Light (CEL) illumination
- โ Engine stalling, stumbling, or poor idle quality
- โ Harsh or erratic automatic transmission shifting
- โ No-start condition where the engine cranks but won’t fire
- โ False sensor codes or communication errors with a scan tool
- โ Reduced fuel economy and overall poor performance
Plug-and-Play Installation: No Dealer Visit Required
Getting your Express 3500 back in service is straightforward. Because we program the module to your VIN, you can often avoid the costly and time-consuming security relearn procedures or programming fees at a dealership. Just follow these simple steps for a successful installation.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the Old PCM: On most 2003 Express/Savana vans, the PCM is located in the engine compartment on the driver’s side, near the firewall.
- Disconnect Connectors: Carefully unlatch and remove the electrical connectors from the old module. Inspect them for any corrosion or bent pins.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into place.
- Reconnect Everything: Firmly re-seat the electrical connectors until they click into place. Reconnect the negative battery terminal.
- Final Check: Turn the key to the ‘ON’ position for 10-15 seconds before starting the engine to allow the systems to initialize. Start your vehicle and enjoy restored performance.
Guaranteed Compatibility
This module is a direct replacement for a wide range of GM vehicles and interchanges with multiple service numbers, ensuring you get the right part. Please provide your VIN upon checkout to guarantee a perfect match.
Replaces Service Numbers: 12581565, 8125815650, 12570557, 12570558, 12576106, 12576869, 12578127, 8125781270, 88864822, 89017733
Fits a wide variety of 2003-2004 GM models including: Chevrolet Express/Silverado, GMC Savana/Sierra, Cadillac CTS, Corvette, Astro, Safari, S10, Blazer, and more. Verify your specific model and engine in the fitment list.