Is your 2006 Buick Rainier or other GM vehicle suffering from frustrating, hard-to-diagnose issues? A persistent check engine light, unexplained stalling, rough idling, or poor fuel economy can often point to a failing Powertrain Control Module (PCM). This isn’t just an inconvenience; it’s a compromise on your vehicle’s reliability and your peace of mind. Put an end to the guesswork and restore your vehicle’s core performance with this fully programmed, ready-to-install engine computer.
We take the complexity out of the repair. Simply provide your vehicle’s VIN during checkout, and our expert technicians will flash this module with the latest, most stable GM software updates specifically for your vehicle. This eliminates the need for expensive dealership programming or specialized tools. You’ll receive a unit that is a direct-fit, plug-and-play solution, designed to get you back on the road quickly and confidently. Regain that smooth, responsive drive you remember and trust your vehicle again.
A Mechanic’s Story: The Phantom Misfire
A customer brought in their Trailblazer (which uses the same PCM) with a random misfire code that had them chasing their tail for weeks. They had replaced plugs, coils, and even injectors, but the problem persisted. After checking all the wiring, we suspected the computer. We installed a pre-programmed module just like this one, and the engine immediately smoothed out. The phantom misfire was gone. It was a powerful reminder that the PCM is the brain of the vehicle, and when it’s not healthy, it can create symptoms that look like something else entirely. A new brain gave the truck a new lease on life.
Warning Signs and How to Overcome Them
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is the definitive solution:
- ✔ Persistent Check Engine Light (CEL) with communication-related Diagnostic Trouble Codes (DTCs) like P0601, P0602, P0605, or P0606.
- ✔ Unexplained engine stalling or hesitation during acceleration.
- ✔ Rough or erratic idling that doesn’t improve with a typical tune-up.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ The vehicle enters ‘limp mode’ with reduced power.
- ✔ Failure to pass emissions testing due to module-related errors.
Guided Installation for a Confident Fix
Installing your new 2006 Rainier Powertrain Control Module is a straightforward process that a confident DIYer can handle. Follow these steps for a smooth replacement:
- Safety First: Begin by disconnecting the negative terminal on your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On the 2006 Rainier and similar platforms (Trailblazer, Envoy), the PCM is typically located on the driver’s side of the engine compartment, near the firewall.
- Disconnect and Remove: Carefully unplug the electrical connectors. There are usually retaining clips that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New PCM: Mount your new, pre-programmed PCM in the same location and securely fasten the bolts.
- Reconnect and Power Up: Plug the electrical connectors firmly into the new module. You should hear a click as they lock into place. Reconnect the negative battery terminal.
- Perform Security Relearn: In many cases, a simple security relearn procedure is needed to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine.
Tailored Fit for Your Ride
This module is a direct replacement for part number 12589585 and is guaranteed to be compatible with the following vehicles and their specified options. We program it to your exact VIN to ensure perfect function.
- BUICK RAINIER 2006: 4.2L (LH engine)
- CHEVROLET COLORADO 2004-2006: (RH firewall)
- CHEVROLET TRAILBLAZER & TRAILBLAZER EXT 2006: 4.2L (LH engine)
- GMC CANYON 2004-2006: (RH firewall)
- GMC ENVOY & ENVOY XL 2006: 4.2L (LH engine)
- HUMMER H3 2006: (RH firewall)
- ISUZU ASCENDER 2006: 4.2L (LH engine)
- ISUZU I-280 2006: (RH firewall)
- ISUZU I-350 2006: (RH firewall)
- SAAB 9-7X 2006: 6 cylinder (LH engine), ID 12569773 or 12597521
This unit also replaces part numbers: 12569773, 12588650, 12589311, 12591647, 12591648, 12593531, 12593532, 12594430, 12594431, 12596783, 12596784, 12597521, 12597776, 12597777, 12600818, 12604438, 12604439, 12606369, 12606373, 12606374, 12606398, 12606399, 19209820, 19209821.
Frequently Asked Questions
Do I need to get this module programmed?
No. The main benefit of our service is that we program the module for you before shipping. Just provide your vehicle’s VIN at checkout, and it will arrive ready to install, saving you a trip to the dealership.
Where is the PCM located on my 2006 Rainier?
On the 2006 Buick Rainier and similar GM models like the Trailblazer and Envoy with the 4.2L engine, the Powertrain Control Module is located in the engine bay, on the driver’s side, attached to the inner fender or firewall.
What is a VIN and why do you need it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your specific vehicle. We use it to load the correct GM-certified software, including any updates, and to configure settings for your engine, transmission, and options. This ensures the 2006 Rainier Powertrain Control Module works perfectly right out of the box.
Will this fix my check engine light?
This module will resolve any Diagnostic Trouble Codes (DTCs) directly caused by a failing PCM, such as internal processor errors (e.g., P0606). If your check engine light is on due to other issues like a faulty sensor or a mechanical problem, those issues will still need to be addressed separately.
Is a security relearn procedure difficult?
Not at all. The GM Passlock/Passkey security relearn is designed to be simple. It typically involves a sequence of turning the key on and off for set periods of time. Most owners can complete it in about 30 minutes without any special tools. We can provide simple instructions upon request.