Restore Your Truck’s Brain and Get Back on the Road
If you’re dealing with frustrating, intermittent engine problems in your 2003 Chevrolet Avalanche 2500, the root cause is often the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing PCM can cause chaos—from random stalling and harsh shifting to a complete no-start situation. It’s the central computer of your vehicle, and when it malfunctions, nothing works right. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded.
We’re offering a dependable, straightforward solution. This PCM, part number 89017733, is not just a replacement part; it’s a complete fix. The biggest hurdle for most DIYers and even professional shops is the programming. Dealerships charge a fortune for this service. We eliminate that step entirely. Simply provide us with your vehicle’s VIN during checkout, and our experts will program the module with the latest, most stable software updates directly from GM. It arrives at your door ready for installation.
A Technician’s Notebook: The Ghost in the Van
I once had a 2003 Savana van in the shop with a problem that was driving the owner crazy. It would run perfectly for days, then suddenly die at a stoplight and refuse to restart for an hour. No consistent codes, just pure frustration. After checking fuel pressure, spark, and wiring harnesses, everything seemed fine. On a hunch, I tapped the PCM casing with a screwdriver handle, and the engine sputtered. The culprit was an internal solder joint failure in the original module, a common issue in these units after years of heat cycles. Replacing it with a properly programmed module solved the problem for good. These intermittent issues are classic signs of a failing PCM.
Is Your Truck’s Brain Failing? Common PCM Symptoms
A faulty PCM can manifest in numerous ways. If you’re noticing any of the following, it’s a strong indicator that your module needs attention. A failing 2003 Avalanche 2500 PCM can be the source of many hard-to-diagnose issues.
- âś” Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error), P0602, P0606, or other communication errors.
- âś” The engine cranks but refuses to start.
- âś” Unexplained stalling, especially when the engine is warm.
- âś” Poor or erratic automatic transmission shifting.
- âś” A noticeable drop in fuel economy.
- âś” Rough idling or misfires that aren’t solved by new plugs or wires.
- âś” Communication loss with your scan tool.
A Straightforward Guide to Installation
One of the best features of our service is that this module arrives ready to install. For a 2003 Avalanche 2500, the PCM is typically located on the driver’s side, under the battery tray. While professional installation is always an option, a confident DIYer can handle this job.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Access the Module: You will likely need to remove the battery and the battery tray to gain clear access to the PCM.
- Disconnect Connectors: Carefully unplug the electrical connectors from the old module. These connectors have locking tabs that must be released before pulling. Do not force them.
- Remove the Old PCM: Unbolt the old module from its mounting bracket.
- Install the New PCM: Mount your new, pre-programmed module in place and securely fasten it.
- Reconnect Everything: Plug the electrical connectors firmly into the new PCM until they click. Reinstall the battery tray and battery, then reconnect the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure so the vehicle recognizes the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Your vehicle’s manual will have the exact steps.
Verified Fitment for Your GM Vehicle
This module is a direct replacement for a wide range of GM trucks, vans, and cars. It replaces multiple service numbers, including: 12581565, 8125815650, 12570557, 12570558, 12576106, 12576869, 12578127, 88864822, and 89017733. Please confirm your vehicle is on the list below for guaranteed compatibility.
- AVALANCHE 2500 2003: Electronic Control Module; (LH front under battery)
- ASTRO / SAFARI (GMC) 2003: Electronic Control Module; (LH front by battery)
- BLAZER S10 / JIMMY S15 2003: Electronic Control Module; (RH front engine compartment)
- CTS 2004: Electronic Control Module; (RH engine compartment), Base, ID 12581565
- CORVETTE 2004: Electronic Control Module; (RH engine compartment), ID 12581565
- EXPRESS / SAVANA VANS (1500/2500/3500) 2003: Electronic Control Module; (LH rear engine compartment)
- S10 / S15 / SONOMA 2003: Electronic Control Module; (RH front engine compartment), 4.3L
- SIERRA / SILVERADO 1500 PICKUP 2003: Electronic Control Module; (LH front under battery), w/4.3L
- SIERRA / SILVERADO 2500/3500 PICKUP 2003: Electronic or Powertrain Control Module; (LH front under battery), gasoline, 8.1L
- SUBURBAN / YUKON XL 2500 2003: Electronic Control Module; (LH front under battery), 8.1L
Ordering a pre-programmed 2003 Avalanche 2500 PCM is the most efficient way to solve complex engine management problems and restore your vehicle’s factory performance and reliability.
Do I need to do any programming or flashing myself?
Do I need to do any programming or flashing myself?
No. The main benefit of our service is that we handle all the programming for you before shipment. Just provide your VIN at checkout, and the module will arrive ready to install with the latest GM software for your specific vehicle.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.
Is the security relearn procedure difficult?
Not at all. It’s a simple procedure that requires no special tools. It typically involves cycling the ignition key and waiting for about 10-15 minutes per cycle. This allows your vehicle’s anti-theft system to synchronize with the new PCM. We can provide general instructions, but it’s always best to consult your owner’s manual for the exact steps for your model.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like code P0601), then yes, this part will resolve the issue. However, if the light is on for another reason (e.g., a bad oxygen sensor or catalytic converter), you will still need to address that separate problem.
How do I know this part will fit my vehicle?
This module fits a wide range of 2003 GM vehicles. Please check the detailed fitment list on this page. Matching your vehicle, year, and engine/options is the first step. Providing your VIN for programming is the final step that guarantees it’s correct for your truck’s specific configuration.