Restore Your Envoy’s Heartbeat and Drive with Confidence
Is your GMC Envoy acting up? A flickering check engine light, frustrating stalls, or a sudden drop in fuel economy can turn a reliable daily driver into a source of constant worry. The Powertrain Control Module (PCM) is the central computer, the very brain of your engine and transmission. When it begins to fail, it can cause a cascade of confusing and unpredictable problems. This isn’t just an inconvenience; it’s a matter of reliability and peace of mind. We’re here to provide the definitive solution: a professionally programmed PCM, tailored specifically to your vehicle’s VIN, ready to restore factory performance and get you back on the road with confidence.
Warning Signs and How to Overcome Them
If your vehicle is experiencing any of the following, a failing PCM could be the culprit. Replacing it can be the key to a lasting fix:
- ✔ Persistent Check Engine Light: Especially for internal module codes like P0601, P0602, P0606, or U0100.
- ✔ Engine Stalling or Misfiring: Unexplained stalling at stops or hesitation during acceleration.
- ✔ Poor Fuel Economy: A sudden, noticeable decrease in your miles per gallon.
- ✔ Harsh or Incorrect Shifting: The transmission may shift erratically, late, or not at all.
- ✔ No-Start Condition: The engine cranks but refuses to start, even with a good battery and starter.
- ✔ Failure to Communicate: Your scan tool can’t connect with the PCM.
Effortless Steps for a Confident Fix
Installing your new 2006 Envoy Powertrain Control Module is a straightforward process you can tackle with basic hand tools. Follow these steps for a successful replacement.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On your 2006 Envoy, the PCM is typically found in the engine bay, on the driver’s side (LH side), near the firewall or inner fender.
- Disconnect Connectors: Carefully release the locking tabs on the electrical harness connectors and gently pull them straight out from the module. Never force them.
- Remove the Old Unit: Use a socket set to remove the bolts or nuts securing the old PCM to its mounting bracket.
- Mount the New PCM: Position your new, pre-programmed module onto the bracket and secure it with the original mounting hardware.
- Reconnect and Secure: Plug the harness connectors firmly back into the new PCM. You should hear or feel a click, indicating they are fully seated.
- Power Up: Reconnect the negative battery terminal and tighten it securely.
- Final Procedure: In many cases, a Crankshaft Variation Relearn (often called a CASE relearn) is required. This can be done with a capable bidirectional scan tool to ensure optimal engine timing and prevent misfire codes.
From the Garage: The Ghost in the Machine
I once had a customer with a 2006 Trailblazer—a sister vehicle to the Envoy—that had a baffling, intermittent misfire. They’d already replaced plugs, coils, and even an injector based on another shop’s advice, but the problem persisted. After hooking up my scope, I saw the injector signal for cylinder 3 was dropping out randomly. The wiring was perfect. The issue was inside the old PCM; the driver circuit was failing under heat. We installed a VIN-programmed 2006 Envoy Powertrain Control Module, performed the CASE relearn, and the ghost was gone. It’s a powerful reminder that sometimes the problem lies with the brain, not the body.
Tailored Fit for Your Ride
This module is a direct-fit replacement, programmed to work seamlessly with your vehicle. Please verify your model and year from the list below. This computer is compatible with the following part numbers: 12569773, 12588650, 12589311, 12589585, 12591647, 12591648, 12593531, 12593532, 12594430, 12594431, 12596783, 12596784, 12597521, 12597776, 12597777, 12600818, 12604438, 12604439, 12606369, 12606373, 12606374, 12606398, 12606399, 19209820, 19209821.
- COLORADO 04-06 (RH firewall)
- RAINIER 06 (LH engine), 4.2L
- HUMMER H3 06 (RH firewall)
- ISUZU ASCENDER 06 4.2L (LH engine)
- ISUZU I-350 06 (RH firewall)
- TRAILBLAZER 06 (LH engine), 4.2L
- TRAILBLAZER EXT 06 (LH engine), 4.2L
- ENVOY XL 06 (LH engine), 4.2L
- ISUZU I-280 06 (RH firewall)
- SAAB 9-7X 06 (LH engine), 6 cylinder
- CANYON 04-06 (RH firewall)
- ENVOY 06 4.2L (LH engine)
Your Questions, Answered
How do I provide my vehicle’s VIN?
Simply enter your 17-digit Vehicle Identification Number (VIN) in the notes section during checkout. If you forget, we will contact you via email to get the necessary information before programming and shipping your module.
Is this part truly plug-and-play?
It’s very close. Because we pre-program the module to your VIN, it eliminates the need for expensive dealer flashing. However, you will likely need to perform a security relearn and/or a Crankshaft Position Sensor Variation (CASE) relearn procedure, which requires a capable scan tool.
Will this fix my specific problem?
This module will correct issues directly caused by a faulty PCM, such as internal processor faults (e.g., P0601), driver circuit failures, and communication errors. It will not fix problems related to other bad sensors or mechanical issues on the vehicle.
What if my original part number is not on the list?
The part numbers listed are the most common, but there can be others. As long as your vehicle’s year, make, and model are on our compatibility list, we can program the correct software for you. Providing your VIN is the most important step for a perfect match.
What tools are required for the installation?
You’ll typically only need basic hand tools, such as a socket set (commonly 10mm) and possibly a flathead screwdriver to help release connector tabs. The physical replacement is a simple bolt-off, bolt-on process.