Restore Peak Performance to Your GM Truck or SUV
Is your 2003 Isuzu Ascender or another compatible GM vehicle suffering from frustrating issues like intermittent stalling, a no-start condition, or a persistent Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the computer that acts as your vehicle’s brain. When it falters, everything from fuel economy to shift points can be affected. This isn’t just an annoyance; it’s a critical component failure that can leave you stranded. This direct-replacement PCM, service number 89017734, is the reliable, long-term solution you need.
A Technician’s Notebook
I remember a 2004 Chevy Tahoe that came into my shop with a ghost of a problem. The owner complained of random no-start conditions—it would be fine for weeks, then refuse to crank for an hour. The only consistent code was a U0100 (Lost Communication with ECM/PCM). We checked grounds, power feeds, and the CAN bus wiring, all of which seemed fine. After hours of diagnostics, we found the issue was internal to the PCM; the main processor would overheat intermittently, causing it to drop communication. This is a common failure point in these P59-style controllers. Replacing the PCM with a properly programmed unit like this one solved the problem permanently.
Is Your Vehicle Showing These Symptoms?
A faulty PCM can manifest in numerous ways. If you’re a professional technician or a hands-on DIYer, you’ve likely seen these before. Here are the most common indicators that your engine computer needs replacement:
- ✔ The Check Engine Light is illuminated with internal module codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Your vehicle cranks but refuses to start, or starts and immediately stalls.
- ✔ Unexplained and sudden drops in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Your scan tool cannot communicate with the PCM, often showing a U0100 code.
- ✔ The engine runs rough, misfires, or hesitates under acceleration.
The Plug-and-Play Advantage: Programmed for You
The biggest hurdle in replacing a modern PCM is the programming. Dealerships often charge hundreds for this service alone. We eliminate that step entirely. When you purchase this module, you simply provide us with your vehicle’s 17-digit VIN. Our technicians will then flash the unit with the latest, most stable software updates directly from GM. This ensures that your new 2003 Isuzu Ascender PCM arrives at your door ready for installation, with all the correct parameters for your specific engine, transmission, and options. It’s a true plug-and-play solution designed to save you time and money.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks and SUVs is a job most people with basic tools can handle in their own driveway. The location is generally easy to access, making for a quick swap.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait a few minutes before starting work.
- Locate the PCM: On most of these vehicles, including the Isuzu Ascender, Chevy Trailblazer, and GMC Envoy, the PCM is located in the engine bay, next to the air filter box. On trucks like the Silverado and Sierra, it’s typically found on the driver’s side, under the battery tray.
- Disconnect Harnesses: Carefully unplug the electrical connectors from the old module. There are typically two or three large harnesses with locking tabs. Use a small flathead screwdriver to gently release the locks if needed.
- Remove Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you will reuse it.
- Install New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: In some cases, a simple 10-minute security relearn procedure is needed. This involves turning the key to the ‘ON’ position for 10 minutes, then off, then starting the vehicle. Instructions are readily available online for your specific model.
Will This Fit My Vehicle?
This module is a direct replacement for service number 89017734 and is also compatible with 89017750, 12582605, 12589463, 12602802, and 28042802. It fits a wide range of GM trucks and SUVs. Please verify your model and year below:
This part fits, but is not limited to, the following vehicles:
- Isuzu Ascender: 2003 (5.3L)
- Chevrolet Avalanche, Silverado, Suburban, Tahoe, Trailblazer EXT, SSR: 2003-2007 (various engines)
- GMC Envoy XL, Sierra, Sierra Denali, Yukon, Yukon XL: 2003-2007 (various engines)
- Cadillac Escalade, ESV, EXT: 2003-2006
- Hummer H2: 2003-2007
Note: For some 2004 and newer models, please match the ID 12602802 on your original part. For 2007 models, this fits the ‘Classic’ body style only.
Frequently Asked Questions
Do I need to do any programming or flashing myself?
No. This is the core benefit of our service. We program the module to your vehicle’s specific VIN before we ship it. It arrives ready for installation.
What information do you need from me after I order?
After you place your order, we will need the 17-digit Vehicle Identification Number (VIN) from your truck or SUV. This is typically found on your driver’s side dashboard (viewable through the windshield) or on your vehicle’s registration.
What is a ‘service number’ and why is it important?
A service number is GM’s internal part number for the component. This module, 89017734, is a direct replacement for several other service numbers, ensuring wide compatibility across the GM platform.
Is this a difficult part to install for a DIYer?
Not at all. For most of the vehicles listed, this is one of the easier modules to replace. It’s typically held in by a few bolts and has easy-to-release connectors. No special tools are required.
Will this fix my specific problem?
If your vehicle is experiencing symptoms of a failed PCM and has stored diagnostic trouble codes like P0601, P0606, or U0100, this part is the correct solution. It resolves issues stemming from an internal failure of the engine computer.