If you’re dealing with frustrating and unpredictable issues in your 2006 Buick Terraza, a failing Engine Control Module (ECM) is often the hidden culprit. As a technician with over two decades of diagnostic experience, I’ve seen countless vehicle owners and even professional shops chase their tails replacing sensors and other parts, only to find the root problem was the vehicle’s computer all along. This isn’t just a replacement part; it’s a definitive solution to restore your minivan’s performance, reliability, and drivability.
The ECM is the brain of your vehicle’s engine, managing everything from fuel mixture and ignition timing to transmission shifting and emissions control. When it starts to fail, the symptoms can be widespread and confusing. This module is your direct-fit, hassle-free answer. We take the guesswork and expensive dealership trips out of the equation by programming the module specifically to your vehicle’s VIN before it ships. This ensures it communicates perfectly with your Terraza’s other systems right out of the box.
Your Straightforward ECM Installation Guide
Replacing the ECM is a manageable job for a DIYer with basic tools. For your 2006 Terraza, the module is typically found in the left-hand (driver’s side) engine compartment. Always consult a service manual for your specific vehicle if you’re unsure.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the ECM: Identify the Engine Control Module. It’s a metal box with several large electrical connectors.
- Disconnect the 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.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the mounting hardware, as you’ll need it for the new unit.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure it with the original hardware.
- Reconnect and Finalize: Plug the wiring harness connectors firmly into the new module until they click into place. Reconnect your battery terminal. Your vehicle may need to complete a drive cycle for all systems to fully sync, but the core programming is already done.
Common Signs of a Failing Engine Computer
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling, stumbling, or running rough for no apparent reason.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Noticeable decrease in fuel economy.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ Communication error codes, such as U0100 (Lost Communication With ECM/PCM).
- ✔ Internal module failure codes, like the notorious P0601 (Internal Control Module Memory Check Sum Error).
Case Study: The Ghost in the Machine
I once had a 2006 Terraza in the bay that was driving its owner crazy. It would stall randomly at red lights, but only when warm. The owner had already replaced the crankshaft position sensor and the idle air control valve based on forum advice. After hooking up my scan tool, I noticed the live data for the coolant temperature sensor would briefly drop to -40°F right before a stall—a classic sign of an internal ECM short. We installed a VIN-programmed 2006 Terraza Engine Control Module, and the problem vanished instantly. It’s a perfect example of how a faulty computer can send you on a wild goose chase.
Verified Compatibility for Your Vehicle
This ECM, part number 12603530, is a direct replacement for a wide range of General Motors vehicles. It is interchangeable with service numbers 12590032, 12602044, 12605843, 12607096, 12630457, and 19210737. While this listing is focused on the 2006 Terraza Engine Control Module, please review the extensive fitment list below to confirm compatibility with other models. Providing your VIN at checkout is essential for us to ensure perfect programming and functionality.
COLORADO 08 Electronic Control Module; (RH firewall)
ENVOY 07-08 Electronic Control Module; 5.3L (LH engine)
ENVOY 08 Electronic Control Module; 4.2L (LH engine), ID 12607096
G6 09 Electronic Control Module; (LH front engine compartment), 3.6L, ID 19210737
MONTE CARLO 06 Electronic Control Module; (lower part of air cleaner box), 3.5L
XLR 09 Electronic Control Module; (RH front engine compartment), ID 12607096
AURA 08-09 Electronic Control Module; (RH firewall), 2.4L, w/hybrid
DTS 06 Electronic Control Module
DEVILLE 05 Electronic Control Module; (LH engine compartment), ID 12590032
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12605843
IMPALA 06 Electronic Control Module; (lower part of air cleaner box), 3.5L
LACROSSE 08-09 Electronic Control Module; (lower air cleaner housing), 5.3L
STS 06 Electronic Control Module; (LH frame rail), 4.4L
TRAILBLAZER 08 Electronic Control Module; (LH engine), ID 12636660
UPLANDER 09 Electronic Control Module; (LH engine compartment), (3.9L)
ISUZU ASCENDER 08 Electronic Control Module; (4.2L, LH engine), ID 19210737
SAAB 9-7X 07 Electronic Control Module; (LH engine), 8 cylinder
TRAILBLAZER 07 Electronic Control Module; (LH engine), 5.3L
ENCLAVE 08 Electronic Control Module; (behind fan shroud), ID 19210737
LUCERNE 08 Electronic Control Module; (lower part of air cleaner box), 4.6L, ID 12607096
MONTE CARLO 06 Electronic Control Module; (lower part of air cleaner box), 3.9L
RAINIER 07 Electronic Control Module; (LH engine), 5.3L
ISUZU ASCENDER 08 Electronic Control Module; (4.2L, LH engine), ID 12607096
CTS 06 Electronic Control Module; (RH engine compartment), V-Series, ID 12603530
STS 08 Electronic Control Module; (LH frame rail), 4.6L
G6 06 Electronic Control Module; (LH front engine compartment), ID 12603530
G6 08 Electronic Control Module; (LH front engine compartment), 3.6L
ION 06 Electronic Control Module; 2.4L (opt LE5)
MALIBU 06 Electronic Control Module; 3.9L
MALIBU 08 Electronic Control Module; new style (emblem in bumper cover), 2.4L, w/hybrid
RELAY 06 Electronic Control Module; (LH engine compartment), 3.9L
VUE 08-09 Electronic Control Module; 2.4L, VIN Z (8th digit, opt LAT)
OUTLOOK 08 Electronic Control Module; (behind fan shroud)
SOLSTICE 06 Electronic Control Module; (LH front frame rail)
VUE 08 Electronic Control Module; 3.6L
VUE 09 Electronic Control Module; 3.6L, VIN 7 (8th digit, opt LY7)
ACADIA 07-08 Electronic Control Module; (behind fan shroud), ID 12607096 (ECM)
AURA 08-09 Electronic Control Module; (RH firewall), 3.6L
ENVOY 08 Electronic Control Module; 4.2L (LH engine), ID 19210737
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12603530
GRAND PRIX 08 Electronic Control Module; (lower air cleaner box), 5.3L
HHR 06 Electronic Control Module; (LH rear engine compartment), 2.4L
STS 08 Electronic Control Module; (LH frame rail), 4.4L
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12590032
ISUZU I-290 08 Electronic Control Module; (RH firewall)
LUCERNE 06 Electronic Control Module; (lower part of air cleaner box), 4.6L
MALIBU 09-10 Electronic Control Module; 2.4L, w/hybrid
UPLANDER 08 Electronic Control Module; (LH engine compartment), (3.9L), ID 19210737
IMPALA 06 Electronic Control Module; (lower part of air cleaner box), 3.9L
MONTANA 06 Electronic Control Module; (LH engine compartment), (SV6), 3.9L
TRAILBLAZER 08 Electronic Control Module; (LH engine), ID 19210737
ENVOY 08 Electronic Control Module; 4.2L (LH engine), ID 12636660
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12602044
TRAILBLAZER 08 Electronic Control Module; (LH engine), ID 12607096
TRAILBLAZER 09 Electronic Control Module; (LH engine), 4.2L
CANYON 08 Electronic Control Module; (RH firewall)
COBALT 06 Electronic Control Module; (LH front engine compartment), 2.4L (VIN B, 8th digit, 4-146)
ISUZU I-370 08 Electronic Control Module; (RH firewall)
MALIBU 09 Electronic Control Module; 3.6L
SRX 08 Electronic Control Module; (LH engine compartment), (4.6L)
SAAB 9-7X 08 Electronic Control Module; (LH engine), 5.3L
ENCLAVE 08 Electronic Control Module; (behind fan shroud), ID 12607096
G6 09 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12607096
IMPALA 08-09 Electronic Control Module; (lower part of air cleaner box), 5.3L
XLR 06 Electronic Control Module; (RH front engine compartment), 4.4L
XLR 08 Electronic Control Module; (RH front engine compartment)
ENVOY 09 Electronic Control Module; (LH engine), 4.2L
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12607096
G6 07 Electronic Control Module; (LH front engine compartment), 3.6L, ID 12618163
LUCERNE 08 Electronic Control Module; (lower part of air cleaner box), 4.6L, ID 19210737
MONTANA 08-09 Electronic Control Module; (LH engine compartment)
PURSUIT 06 Electronic Control Module; (LH front engine compartment), 2.4L
VUE 10 Electronic Control Module; 3.6L
ACADIA 08 Electronic Control Module; (behind fan shroud), ID 19210737 (PCM)
DTS 08 Electronic Control Module
TERRAZA 06 Electronic Control Module; (LH engine compartment), 3.9L
TRAILBLAZER 07 Electronic Control Module; (LH engine), 6.0L
SAAB 9-7X 08 Electronic Control Module; (LH engine), 6.0L
HUMMER H3 08 Electronic Control Module; (RH firewall)
MALIBU 08 Electronic Control Module; new style (emblem in bumper cover), 3.6L
UPLANDER 08 Electronic Control Module; (LH engine compartment), (3.9L), ID 12607096
UPLANDER 06 Electronic Control Module; (LH engine compartment), 3.9L
What is VIN programming?
What is VIN programming?
VIN programming is the process where we load your vehicle’s specific Vehicle Identification Number (VIN) and the latest GM-certified software onto the ECM. This ensures the module is a perfect match for your vehicle’s factory settings, security system (like Passlock/VATS), and options. It makes the installation plug-and-play, eliminating the need for an expensive trip to the dealer for programming.
Do I need to do anything after installing this ECM?
In most cases, no additional programming is required. However, some vehicles may require a security relearn procedure or a crank position sensor relearn, which can typically be done without special tools. Instructions are widely available online, or you can consult your service manual. The vehicle will adapt as you drive it through a normal drive cycle.
Will this part fix my check engine light?
If the check engine light is caused by a faulty ECM (e.g., codes P0601-P0606 or communication errors), then yes, this module is designed to resolve that. However, the check engine light can be triggered by hundreds of potential issues. It’s always best to have the codes scanned with a diagnostic tool to confirm the source of the problem before ordering parts.
Where is the ECM located on my 2006 Buick Terraza?
For the 2006 Terraza with the 3.9L engine, the Engine Control Module is typically located in the engine compartment on the driver’s side (LH side), often near the firewall or air filter housing.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically add it as a note during checkout or send it to us in a message referencing your order number. We cannot program and ship the module without it.