Is Your Buick Rendezvous Running Rough?
As a technician with over two decades of experience under the hood, I’ve seen countless vehicles sidelined by a faulty Engine Control Module (ECM). If your 2004-2006 Buick Rendezvous is experiencing frustrating issues like intermittent stalling, a persistent check engine light, poor fuel mileage, or a complete no-start condition, the ECM is a very likely culprit. This isn’t just a part; it’s the brain of your engine’s operations, and when it fails, it can cause a cascade of confusing problems.
This listing is for a reliable, genuine OEM Engine Control Module, service number 12588472 (interchangeable with 12581144, 12592124, 19260507). We take the biggest headache out of the repair process: programming. Simply provide your vehicle’s VIN at checkout, and my team will flash this module with the latest, most stable software updates directly from GM. This ensures it arrives at your door ready for a straightforward installation, saving you a costly trip to the dealership and getting your vehicle back to its dependable self.
Common Signs of a Failing ECM
A bad engine computer can manifest in numerous ways. Before you spend hours chasing down sensor issues, see if your vehicle is exhibiting any of these classic symptoms of ECM failure. In my shop, these are the red flags I look for first.
- ✔ Check Engine Light is on with internal processor codes (like P0601, P0606).
- ✔ Engine stalls for no apparent reason, either while driving or at idle.
- ✔ Complete no-start condition where the engine cranks but won’t fire up.
- ✔ Noticeable drop in fuel economy.
- ✔ Transmission shifting problems or harsh engagement.
- ✔ Communication errors with scan tools (e.g., U0100).
- ✔ Misfires or rough running that can’t be traced to plugs, coils, or injectors.
From the Diagnostic Bay
I remember a 2005 Rendezvous that came in on a tow truck. The owner had already replaced the crank sensor and two ignition coils trying to solve a persistent no-start problem. The engine would crank all day but never catch. His scanner wasn’t pulling any codes, which added to the confusion. After confirming fuel pressure and spark at the plug wire, I hooked up my professional-grade scanner. The key was that I couldn’t communicate with the ECM at all. It was completely offline. We installed one of our pre-programmed ECMs, performed the security relearn, and the engine fired up on the first try. It’s a classic case where the root cause wasn’t a sensor, but the computer that reads them.
A Straightforward Guide to Installation
Replacing the 2004-2006 Rendezvous ECM is a manageable job for a DIYer with basic tools. The pre-programming we perform saves you the most difficult step.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for the system capacitors to discharge.
- Locate the ECM: On the Buick Rendezvous, the ECM is typically found in the engine compartment, on the driver’s side, often near or under the air cleaner housing.
- Disconnect Connectors: Carefully release the locking tabs on the electrical harness connectors and pull them straight out from the module. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the mounting hardware that secures the old ECM to its bracket. Remove the old unit from the vehicle.
- Install the New Module: Mount your new, pre-programmed ECM in place and secure it with the original hardware. Reconnect the electrical connectors, ensuring they click securely into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure (often called a Passlock or anti-theft relearn). This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows your vehicle’s security system to recognize the new ECM. After this, your vehicle should start and run correctly.
Verified Vehicle Compatibility
This ECM is a direct fit for a range of GM vehicles equipped with the 3.6L engine. Please verify your part number or consult the list below. Providing your VIN is the best way to guarantee a perfect match.
- Buick Allure: 2005-2008 (3.6L)
- Buick LaCrosse: 2005-2008 (3.6L)
- Buick Rendezvous: 2004-2006 (3.6L)
- Cadillac CTS: 2004-2007 (Base models, check ID)
- Cadillac SRX: 2004-2006 (3.6L)
Is this a brand new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. We inspect each unit to ensure it’s fully functional before programming and shipping. This provides OEM reliability at a fraction of the cost.
Do I need to do any programming?
No! The main benefit of our service is that we program the module to your car’s specific VIN before it ships. The only procedure you may need to perform is a simple key/security relearn, which requires no special tools.
Where do I provide my VIN?
Please enter your 17-digit Vehicle Identification Number (VIN) in the notes section during checkout or send it to us in a message after your purchase. We cannot ship your order without it.
What if I have an anti-theft system?
This module is compatible with the factory anti-theft system. After installation, you will need to perform a standard security relearn procedure, which syncs the module to your vehicle. Instructions are readily available online or in your vehicle’s service manual.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your old ECM (e.g., DTC P0601), then this part is the correct solution. It’s crucial to properly diagnose the issue first, as a check engine light can also be caused by faulty sensors or wiring.