Restore Your GM Truck’s Performance and Reliability
Is your 2003 GMC Envoy XL or other GM truck suffering from baffling electrical gremlins? A faulty Powertrain Control Module (PCM), the central computer of your vehicle, is often the hidden culprit behind poor performance, erratic behavior, and a persistent Check Engine Light. As a technician with over two decades of experience, I’ve seen firsthand how a failing PCM can cause symptoms that mimic other, more expensive problems. This replacement PCM, part number 89017734, is the definitive solution to get your vehicle running right again.
The biggest challenge with replacing a PCM has always been the expensive and time-consuming programming required at a dealership. We eliminate that step entirely. Before we ship this module, we will program it with the latest official GM software updates, specifically matched to your truck’s Vehicle Identification Number (VIN). This ensures seamless communication with your vehicle’s other modules and provides a true plug-and-play repair. You get a reliable part that is ready for installation the moment it arrives at your door.
Case Study: A Tricky Diagnosis
A customer brought in a 2004 Sierra 1500 with a complaint of harsh shifting and an intermittent no-start condition. They had already replaced the transmission fluid and filter, and even a crankshaft position sensor, with no luck. The scanner showed a U0100 (Lost Communication with ECM/PCM) and a P0601 (Internal Control Module Memory Check Sum Error). These codes point directly to the computer itself. Instead of chasing more phantom issues, we installed a VIN-programmed PCM. The shifting smoothed out immediately, the starting issue vanished, and the codes never returned. It was a one-part fix for a problem that had seemed impossibly complex.
Is Your GM Truck or SUV Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is your likely solution:
- âś” Persistent Check Engine Light with codes like P0601, P0606, or U0100.
- âś” Unexplained drop in fuel economy.
- âś” Engine stalling, misfiring, or running rough.
- âś” Harsh or erratic automatic transmission shifting.
- âś” Complete no-start condition where the engine cranks but won’t fire.
- âś” Communication issues with diagnostic scan tools.
A Straightforward Guide to Installation
Installing your new 2003 Envoy XL PCM is a job most DIYers can handle in under an hour. Follow these steps for a successful replacement.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the PCM: On the 2003 Envoy XL, the PCM is typically found in the engine bay, next to the air filter box. On most GM trucks like the Silverado or Sierra, it’s located under the hood on the driver’s side, often near the battery.
- Disconnect the Connectors: Carefully unclip and remove the electrical wiring harnesses from the old module. These connectors have locking tabs that need to be released before they can be pulled away.
- Swap the Module: Unbolt the old PCM from its mounting bracket and set it aside. Secure the new module in its place.
- Reconnect and Finalize: Plug the wiring harnesses firmly into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure. Turn the key to the ‘ON’ position for 10-15 minutes, then turn it ‘OFF’ for 10 seconds. Repeat this cycle three times. On the fourth try, the vehicle should start and run normally.
Verified Vehicle Compatibility
This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. It fits a wide range of GM, Isuzu, and Hummer vehicles. Please verify your model and options below:
ESCALADE, ESV, EXT 03-06
HUMMER H2 03-07
ISUZU ASCENDER 03 (5.3L)
SIERRA 1500, 2500, 3500 & DENALI 03-07 (Classic Style)
SILVERADO 1500, 2500, 3500 03-07 (Classic Style)
SSR 03
SUBURBAN 1500, 2500 03-06
TAHOE 03-06
TRAILBLAZER EXT 03 (5.3L)
ENVOY XL 03 (5.3L)
YUKON & YUKON XL 1500, 2500 03-06
Note: For some 2004 models, please verify your original module has ID 12602802 for guaranteed compatibility.
Frequently Asked Questions
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information.
Do I need to do anything else after installing this PCM?
In most cases, you will only need to perform the simple security relearn procedure detailed in our installation guide. This syncs the new PCM with your vehicle’s anti-theft system and does not require any special tools.
What is a PCM and why does it fail?
The Powertrain Control Module (PCM) is your vehicle’s main computer, managing engine and transmission functions. Over time, heat, vibration, and electrical surges can cause internal components on the circuit board to fail, leading to performance issues.
My old part number isn’t 89017734. Will this still work?
Yes. This module is a direct replacement for several service numbers, including 89017750, 12582605, 12589463, and 12602802. As long as your vehicle is on the compatibility list, this part will function correctly once programmed to your VIN.
Is this a brand new part?
This is a high-quality, tested replacement part that has been verified to meet or exceed original equipment specifications. It is loaded with new, updated software from GM for optimal performance.