Is Your Truck Running Rough? It Could Be The PCM.
If your 2004-2006 GMC Canyon, Chevy Colorado, or Hummer H3 is experiencing baffling issues like stalling, erratic shifting, a persistent check engine light, or a no-start condition, the root cause is often the very brain of your vehicle: the Powertrain Control Module (PCM). This essential component manages everything from fuel injection and ignition timing to transmission shift points. When it fails, it can create a cascade of problems that are often misdiagnosed, leading to wasted time and money on unnecessary parts.
This is a direct-fit replacement Powertrain Control Module, part number 12606374, for a wide range of GM trucks and SUVs. We take the guesswork and hassle out of the repair process. Unlike a generic module from a parts store or a salvage yard, this unit comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We flash it with the latest, most stable software updates directly from GM, ensuring optimal performance, fuel economy, and emissions control right out of the box. This plug-and-play solution eliminates the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
We had a 2005 Chevy Colorado in the shop that was driving the owner crazy. It had a random misfire code (P0300) and would occasionally stall at stoplights. The owner had already replaced the spark plugs, coils, and even the fuel pump based on advice from various forums. The problem persisted. When we hooked up our professional scan tool, we noticed the 5-volt reference signal to the throttle position sensor was fluctuating wildly. This signal comes directly from the PCM. Instead of a faulty sensor, the PCM itself was failing internally, causing the erratic data and confusing the engine. A new, correctly programmed PCM fixed the issue instantly. It’s a classic case of treating the source of the problem, not just the symptoms.
Diagnosing a Faulty 2004-2006 Canyon PCM
A failing PCM can manifest in numerous ways, often mimicking other component failures. If you’re experiencing any of the following symptoms, your powertrain control module should be a primary suspect. This information is also relevant for the Chevy Colorado, Hummer H3, Isuzu Ascender, and other vehicles listed in the fitment guide.
- ✔ Check Engine Light: The most common sign. You may see codes related to sensors, communication errors (U-codes), or internal module failure (P06xx codes).
- ✔ Engine Stalling or Misfiring: The engine may stall for no apparent reason, either while driving or at idle. Random misfires can also occur as the PCM struggles to control ignition timing.
- ✔ Poor Fuel Economy: Incorrect fuel and air mixture calculations can lead to a sudden and significant drop in your truck’s MPG.
- ✔ Harsh or Failed Shifting: The PCM also controls the transmission. A faulty module can cause delayed engagement, hard shifts, or getting stuck in one gear.
- ✔ No-Start Condition: In severe cases, the PCM can fail completely, preventing the engine from starting at all. You may have power to the accessories, but the engine won’t crank or fire.
- ✔ Communication Issues: Your OBD-II scanner may be unable to communicate with the vehicle’s computer, a strong indicator of PCM failure.
The Simple, Reliable Solution
Our process is designed to get you back on the road quickly and affordably. When you purchase this module, you simply provide us with your vehicle’s VIN. Our technicians then use that information to flash the unit with the precise software your truck needs. This ensures all factory settings and parameters are correct for your specific engine, transmission, and emissions equipment. The module arrives at your door ready for installation. In most cases, after installation, you will need to perform a simple security relearn procedure (often called a CASE relearn), which can be done without special tools. This synchronizes the new PCM with your vehicle’s anti-theft system and crankshaft position sensor.
Guaranteed Fitment
This module is a direct replacement for a wide range of part numbers and fits the following vehicles. Please verify your vehicle is on the list before ordering.
- GMC CANYON: 2004-2006 (Electronic Control Module; RH firewall)
- CHEVROLET COLORADO: 2004-2006 (Electronic Control Module; RH firewall)
- HUMMER H3: 2006 (Electronic Control Module; RH firewall)
- BUICK RAINIER: 2006 (Electronic Control Module; LH engine, 4.2L)
- GMC ENVOY / ENVOY XL: 2006 (Electronic Control Module; 4.2L, LH engine)
- CHEVROLET TRAILBLAZER / TRAILBLAZER EXT: 2006 (Electronic Control Module; LH engine, 4.2L)
- ISUZU ASCENDER: 2006 (Electronic Control Module; 4.2L, LH engine)
- ISUZU I-280 / I-350: 2006 (Electronic Control Module; RH firewall)
- SAAB 9-7X: 2006 (Electronic Control Module; LH engine, 6 cylinder)
This part replaces the following OEM 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.
Frequently Asked Questions
Do I need to have this PCM programmed?
No. This module comes pre-programmed to your vehicle’s VIN. Simply provide your VIN to us after purchase, and we will flash the unit with the correct GM software before shipping it to you.
Where is the PCM located on my 2004-2006 GMC Canyon?
On the 2004-2006 Canyon, Colorado, and Hummer H3, the PCM (also called ECM) is typically located on the right-hand (passenger side) of the firewall in the engine bay. On Trailblazer/Envoy platforms, it’s usually on the left-hand (driver side) of the engine.
What is a CASE relearn and will I need to do it?
A CASE (Crankshaft Angle Sensor Error) relearn synchronizes the new PCM with the crankshaft position sensor. This is required for the engine to run correctly and to clear certain diagnostic codes. While some vehicles may start and run without it, it is highly recommended. Many mid-level OBD-II scan tools have this function, or a qualified mechanic can perform it.
How do I provide my VIN after purchase?
After you complete your purchase, we will send you an email with instructions, or you can send us a message through the platform with your 17-digit VIN. Please double-check the VIN for accuracy before sending.
Will this PCM fix my truck’s problem for sure?
This PCM will fix any issues directly caused by a faulty module. However, it’s crucial to ensure your vehicle has been properly diagnosed. This part will not fix problems related to bad sensors, wiring issues, or mechanical failures.