Restore Your Vehicle’s Core Performance and Reliability
If you’re dealing with frustrating issues like a persistent check engine light, erratic engine behavior, or a no-start condition in your 2006 Buick Rainier, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your engine and transmission, its proper function is non-negotiable. This replacement PCM is the definitive solution, arriving at your door pre-programmed with the latest GM software updates specifically for your vehicle’s VIN. This eliminates the need for an expensive trip to the dealership for programming, getting you back on the road with confidence.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Trailblazer (which shares this exact PCM with the Rainier) with a complaint of intermittent stalling at stoplights and harsh 1-2 shifts. No specific transmission codes were present, only a generic P0606 (PCM Processor Fault). After checking all the basics—fuel pressure, wiring, and grounds—we focused on the module itself. In my shop, I’ve seen hundreds of these GMT360-platform PCMs fail due to heat cycles and vibration from their location on the engine block. We swapped in a pre-programmed module like this one, performed the security relearn, and the stalling and shifting problems were gone instantly. It’s a classic failure that often mimics other, more expensive component issues.
Is Your Vehicle Showing These Symptoms?
A faulty PCM can cause a wide range of problems. If you’re experiencing any of the following, this module is likely the solution you need.
- ✔ Unexplained Check Engine Light (CEL) illumination
- ✔ Stored diagnostic trouble codes (DTCs) such as P0601, P0602, P0606, or U0100
- ✔ Vehicle refuses to start or has intermittent starting problems
- ✔ Poor or erratic automatic transmission shifting
- ✔ Noticeable decrease in fuel economy
- ✔ Engine stalling, stumbling, or running rough
- ✔ Failure to pass a state emissions inspection
A Straightforward Guide to Installation
Replacing your 2006 Rainier Powertrain Control Module is a manageable job for a DIYer with basic hand tools. Our pre-programmed service makes it even simpler. Follow these general steps to get your vehicle running right.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On the 4.2L Rainier, the PCM is typically located on the driver’s side (LH) of the engine block.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released before pulling. Avoid forcing them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Plug the wiring harness connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: This is a critical step. You will need to perform the GM Security Relearn Procedure (often called the Passlock or Passkey relearn) to sync the new PCM with your vehicle’s anti-theft system. This procedure typically takes 30 minutes and does not require special tools. Instructions are readily available online or in service manuals.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM trucks and SUVs, ensuring broad compatibility. Please verify your vehicle is on this list. This part replaces service 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.
- 2006 Buick Rainier (4.2L, LH engine)
- 2006 Chevrolet Trailblazer / EXT (4.2L, LH engine)
- 2004-2006 Chevrolet Colorado (RH firewall)
- 2006 GMC Envoy / XL (4.2L, LH engine)
- 2004-2006 GMC Canyon (RH firewall)
- 2006 Hummer H3 (RH firewall)
- 2006 Isuzu Ascender (4.2L, LH engine)
- 2006 Isuzu I-280 / I-350 (RH firewall)
- 2006 Saab 9-7X (6 cylinder, LH engine)
Do I need to program this module?
Do I need to program this module?
No. We handle the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN during checkout, and we will flash the module with the latest GM-certified software for your specific vehicle. It arrives ready for installation.
What is a security relearn and is it difficult?
A security relearn is a required procedure that syncs the new PCM to your vehicle’s anti-theft system. Without it, the vehicle will not start. It’s a simple process that involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’ for 10 seconds, and repeating this sequence two more times. It takes about 30 minutes and requires no special scan tools.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine and transmission functions. A failing module can cause harsh shifting, delayed engagement, or incorrect gear selection. If your transmission issues are electronic in nature and not caused by an internal mechanical failure, this module is very likely the solution.
Is this a brand new part?
This is a professionally reconditioned OEM part that has been rigorously tested to meet or exceed original factory specifications. It is loaded with new, updated software from GM to ensure optimal performance and longevity.