Restore Your Hummer’s Brain and Get Back on the Trail
If you’re dealing with frustrating issues like a rough idle, poor fuel mileage, erratic shifting, or a no-start condition in your 2006 HUMMER H3, the root cause is often a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty engine computer can create a cascade of problems that are difficult to diagnose. It’s the central command center for your engine and transmission, and when it falters, your vehicle’s performance and reliability suffer.
This isn’t just a replacement part; it’s a complete solution. We take the hassle and high cost out of the equation by pre-programming this PCM specifically for your vehicle. Simply provide us with your Vehicle Identification Number (VIN) after purchase, and our experts will flash the module with the latest, most stable software updates directly from GM. This ensures perfect communication between your engine, transmission, and other onboard systems, restoring the smooth operation you expect from your Hummer. Forget expensive trips to the dealership for programming—this module arrives at your door ready for a straightforward installation.
Case Study: A Tricky Diagnosis
I remember a 2006 H3 that came into the shop with a complaint of intermittent stalling at stoplights and a weird, delayed shift from 2nd to 3rd gear. The owner had already replaced the throttle body and a transmission speed sensor, but the problem persisted. There were no hard codes, just a pending P0606 (PCM Processor Fault). After checking all the wiring and grounds, we connected a scope and saw erratic voltage signals coming from the PCM. We swapped in a pre-programmed module just like this one, and the difference was immediate. The idle smoothed out, the shifting became crisp, and the stalling disappeared. It’s a classic example of how a failing PCM can mimic other component failures, making it a frustrating and expensive chase for both DIYers and pros.
Is Your Hummer Showing These PCM Failure Signs?
- âś” Unexplained Check Engine Light illumination.
- âś” Stored diagnostic trouble codes (DTCs) like P0601, P0602, P0606, or U0100.
- âś” The engine cranks but refuses to start.
- âś” Noticeable decrease in fuel economy.
- âś” Harsh or delayed automatic transmission shifting.
- âś” Rough or unstable engine idle.
- âś” Intermittent stalling or hesitation during acceleration.
A Straightforward Guide to Your PCM Installation
- âś” Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow the system to fully discharge.
- âś” Locate the PCM: On the 2006 HUMMER H3, the PCM is typically located on the right-hand (passenger side) of the firewall in the engine bay.
- âś” Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- âś” Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in by a few small bolts.
- âś” Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it. Reconnect the wiring harnesses, making sure they click securely into place.
- âś” Final Steps: Reconnect the negative battery terminal. It’s a good idea to perform a security relearn procedure if required for your specific vehicle, which often involves turning the key to the ‘ON’ position for 10-15 minutes. Start the engine and let it idle to confirm proper operation.
Verified Vehicle Compatibility List
This module is a direct replacement for part number 12591647 and is also compatible with a wide range of other GM part numbers. It is guaranteed to fit the following vehicles:
- HUMMER H3: 2006 (Electronic Control Module; RH firewall)
- Chevrolet Colorado: 2004-2006 (Electronic Control Module; RH firewall)
- GMC Canyon: 2004-2006 (Electronic Control Module; RH firewall)
- Buick Rainier: 2006 (4.2L, Electronic Control Module; LH engine)
- Chevrolet Trailblazer / EXT: 2006 (4.2L, Electronic Control Module; LH engine)
- GMC Envoy / XL: 2006 (4.2L, Electronic Control Module; LH engine)
- Isuzu Ascender: 2006 (4.2L, Electronic Control Module; LH engine)
- Isuzu I-280: 2006 (Electronic Control Module; RH firewall)
- Isuzu I-350: 2006 (Electronic Control Module; RH firewall)
- Saab 9-7X: 2006 (6 cylinder, ID 12569773 or 12597521, Electronic Control Module; LH engine)
This unit is interchangeable with the following part numbers: 12569773, 12588650, 12589311, 12589585, 12591648, 12593531, 12593532, 12594430, 12594431, 12596783, 12596784, 12597521, 12597776, 12597777, 12600818, 12604438, 12604439, 12606369, 12606373, 12606374, 12606398, 12606399, 19209820, 19209821.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to load the exact, correct GM-certified software for your H3’s specific configuration, including engine, transmission, and emissions equipment. This ensures seamless integration and performance right out of the box.
Is this a simple plug-and-play installation?
Yes! Because we program the module to your VIN before shipping, you will not need to take it to a dealer or mechanic for additional programming. In most cases, a simple security relearn procedure (which you can do yourself) may be required after installation.
Do I need to send my old PCM back?
No core charge is required for this part. You can keep your old module, though we always recommend recycling old electronics responsibly.
Will this fix my transmission shifting problems?
The PCM controls both the engine and the transmission. If your shifting issues are caused by faulty electronic commands from a failing computer, then this new module is very likely to solve the problem by restoring proper communication.
What if my part number isn’t an exact match to 12591647?
No problem. This PCM is a direct replacement for a long list of interchangeable GM part numbers, which are listed above. As long as your vehicle is on the compatibility list, this module will work perfectly.