Restore Your Van’s Core Performance and Reliability
If your 2005-2007 Chevrolet Express 3500 is giving you headaches with stalling, erratic shifting, a persistent check engine light, or a frustrating no-start condition, the problem often points directly to a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty PCM can sideline a perfectly good workhorse. This isn’t just an inconvenience; it’s lost time and money. This module is the vehicle’s brain, and when it malfunctions, the entire powertrain suffers. Our replacement Express 3500 Van PCM is the definitive, hassle-free solution to get you back on the road and back to business.
The biggest hurdle in replacing a PCM has always been the programming. Historically, you’d have to buy the part, install it, and then have your van towed to a dealership for an expensive flashing procedure. We eliminate that entire step. Before we ship this module to you, we program it with the latest official GM software updates, specifically matched to your van’s unique Vehicle Identification Number (VIN). This means it arrives at your door ready for installation, saving you hundreds of dollars in dealer fees and diagnostic time. It’s the smart, efficient fix for both professional mechanics and dedicated DIYers.
Case Study: A Tricky Diagnosis
I remember a fleet customer with a 2006 Express 3500 that had a ghost of a problem. The van would randomly refuse to start, but only after it was hot. No check engine light, no consistent codes. We checked the fuel pump, ignition system, and starter—all were fine. After hours of diagnostics, we hooked up a scope to the PCM’s power and ground circuits. We discovered that heat soak was causing an internal voltage drop inside the module itself. We installed one of our pre-programmed PCMs, and the van has been starting reliably for that customer ever since. It’s a reminder that intermittent, hard-to-trace issues often lead back to the vehicle’s central computer.
Is Your Express Van Showing These Red Flags?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs attention. Often, you’ll see specific Diagnostic Trouble Codes (DTCs) on a scan tool.
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Memory Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine stalls unexpectedly, either at idle or while driving.
- ✔ Failure to pass an emissions or smog test.
- ✔ Communication errors with your scan tool (e.g., U0100).
A Straightforward Guide to Installation
Replacing the Express 3500 Van PCM is a manageable job for someone with basic mechanical skills. The module is located in the engine compartment on the driver’s side. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On the Express and Savana vans, the PCM is typically found in the rear of the engine compartment on the driver’s side, mounted to a bracket.
- Disconnect the Connectors: The PCM will have several large multi-pin electrical connectors. Each has a locking tab or lever. Carefully release the locks and pull the connectors straight out. Never force them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you will need it for the new module.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the electrical connectors back into the new module until they click and the locking levers are secure. Reconnect the negative battery terminal.
- Final Step: In some cases, a security relearn procedure may be necessary for the vehicle to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for specific steps if required.
Verified Compatibility for Your GM Vehicle
This module is a direct replacement for part numbers 12589462, 12602801, and 89017749. It is guaranteed to fit the following vehicles and configurations. Please confirm your model and engine to ensure proper fitment.
AVALANCHE 2500 05-06 | BLAZER S10 05 | EXPRESS 1500 VAN 05-07 | EXPRESS 2500 VAN 05-07 (Gasoline) | EXPRESS 3500 VAN 05-07 (Gasoline) | SILVERADO 1500 PICKUP 05-07 (Classic, 4.3L) | SILVERADO 2500 PICKUP 05-07 (Classic, 8.1L) | SILVERADO 3500 PICKUP 05-07 (Classic, 8.1L) | SUBURBAN 2500 05-06 (8.1L)
GMC:
JIMMY S15 05 | SAFARI 05 | SAVANA 1500 VAN 05-07 | SAVANA 2500 VAN 05-07 (Gasoline) | SAVANA 3500 VAN 05-07 (Gasoline) | SIERRA 1500 PICKUP 05-07 (Classic, 4.3L) | SIERRA 2500 PICKUP 05-07 (Classic, 8.1L) | SIERRA 3500 PICKUP 05-07 (Classic, 8.1L) | YUKON XL 2500 05-06 (8.1L)
Other GM:
ASTRO 05 | CTS 04-05 (V-Series, check ID)
Frequently Asked Questions
Frequently Asked Questions
Is this module truly plug-and-play?
Yes. Because we program the module to your specific VIN before shipping, it arrives ready to be installed without requiring a trip to the dealer for programming. In some cases, a simple key-cycle security relearn may be needed, which you can do yourself in minutes.
Where do I find my VIN and how do I provide it?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on a placard on the driver’s side dashboard visible through the windshield. After you complete your purchase, you will receive instructions on how to send us your VIN so we can program your module.
What if my original part number is not an exact match to 12589462?
This module is also a direct replacement for part numbers 12602801 and 89017749. As long as your vehicle is on our compatibility list and your old module has one of these three part numbers, this part will work perfectly.
Do I need to send my old PCM (core) back?
No core charge or return is required for this purchase. You can keep or responsibly dispose of your old module.