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Restore Your Van’s Core Performance and Reliability
As a technician with over two decades of experience, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can bring a dependable workhorse like the 2005-2007 Express 2500 Van to a grinding halt. It’s the brain of your engine and transmission, and when it starts to go, you’ll experience a host of frustrating issues—from erratic shifting and poor fuel economy to a dreaded no-start condition that leaves you stranded. This isn’t just an inconvenience; for a work van, it’s lost time and money.
This isn’t just a replacement part; it’s a direct solution. We offer a reliable, fully tested Powertrain Control Module, part number 12602801, that arrives at your door ready to install. The biggest hurdle for most DIYers and even some shops is the programming. We handle that for you. Simply provide your vehicle’s VIN at checkout, and our experts will flash the module with the latest, most stable software updates from GM. This ensures optimal communication between all your vehicle’s systems, restoring the performance and efficiency you depend on.
The Advantage of a Pre-Programmed Express 2500 Powertrain Control Module
Why is a pre-programmed module so critical? In my shop, I’ve seen customers try to save a few dollars with a junkyard module, only to find it’s incompatible or requires an expensive trip to the dealership for flashing—a trip that can cost hundreds of dollars and waste a full day. Our solution eliminates that entire process. Your new Express 2500 Powertrain Control Module arrives ready to be installed, making this a straightforward, cost-effective repair you can confidently perform yourself.
A local contractor brought his ’06 Savana 2500 into my bay with a maddeningly intermittent problem. It would randomly stall at low speeds, sometimes refusing to restart for 10-15 minutes. No check engine light, no consistent codes. We checked fuel pressure, ignition components, and wiring harnesses—all perfect. The symptoms pointed to a thermal failure inside the PCM. After swapping in a pre-flashed module like this one, the problem vanished completely. The original PCM’s internal processor was failing only when it reached a specific temperature, a classic sign of electronic component fatigue. This simple swap saved him from potentially replacing dozens of other perfectly good parts.
Is Your Van’s Brain Failing? Common PCM Symptoms
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, your module is the likely culprit:
- ✔ Check Engine Light is on with codes like P0601, P0606, or U0100.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine stalls, stumbles, or misfires intermittently.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Installation
Installing your new Express 2500 Powertrain Control Module is a manageable job for a DIYer with basic tools. Follow these steps to get your van back in service quickly.
- 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 most Express and Savana vans, the PCM is located in the engine compartment on the driver’s side, near the firewall or master cylinder.
- Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harness connectors from the old module. These connectors have locking tabs; be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, you will need to perform a simple security or anti-theft relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the new PCM to recognize your vehicle’s key. Consult your owner’s manual for the specific procedure for your van.
Verified Vehicle Compatibility
This module, service number 12602801, is a direct replacement for part numbers 12589462 and 89017749. It is guaranteed to fit a wide range of GM trucks and vans. Please confirm your vehicle is on the list below:
AVALANCHE 2500 05-06 (LH front under battery)
BLAZER S10/JIMMY S15 05 (RH front engine compartment)
CTS 04-05 V-Series (RH engine compartment, ID 12589462 or 12602801)
EXPRESS 1500 VAN 05-07 (LH rear engine compartment)
EXPRESS 2500 VAN 05-07 Gasoline (LH rear engine compartment)
EXPRESS 3500 VAN 05-07 Gasoline (LH rear engine compartment)
SAFARI (GMC) 05 (LH front by battery)
SAVANA 1500 VAN 05-07 (LH rear engine compartment)
SAVANA 2500 VAN 05-07 Gasoline (LH rear engine compartment)
SAVANA 3500 VAN 05-07 Gasoline (LH rear engine compartment)
SIERRA 1500 PICKUP 05-07 Classic Style, 4.3L, w/o hybrid (LH front under battery)
SIERRA 2500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
SIERRA 3500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
SILVERADO 1500 PICKUP 05-07 Classic Style, 4.3L, w/o hybrid (LH front under battery)
SILVERADO 2500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
SILVERADO 3500 PICKUP 05-07 Classic Style, 8.1L Gasoline (LH front under battery)
SUBURBAN 2500 05-06 8.1L (LH front under battery)
YUKON XL 2500 05-06 8.1L (LH front under battery)
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you can send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information.
Is this a plug-and-play part?
Yes, this module is pre-programmed to your vehicle’s VIN. However, on most GM vehicles, you will need to perform a simple security relearn procedure which takes about 30 minutes with just the ignition key.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls engine performance and transmission shift points. If the module is faulty, it can cause poor shifting, which a new, correctly programmed module will resolve.
What if I have other modifications on my vehicle?
This module is programmed with the latest standard GM factory software for your specific VIN. It is not designed for vehicles with significant aftermarket modifications that require special software adjustments.
Do I need to send my old PCM (core) back?
No core charge or return is required for this particular part. You can recycle your old module locally.