Restore Peak Performance to Your Cadillac XLR
Is your 2008-2009 Cadillac XLR running rough, stalling unexpectedly, or showing a persistent Check Engine Light? As a technician with over two decades of experience, I’ve seen firsthand how a failing Engine Control Module (ECM) can cause a cascade of frustrating and hard-to-diagnose problems. The ECM is the brain of your vehicle’s engine, managing everything from fuel mixture and ignition timing to transmission shifts. When it falters, your car’s performance, reliability, and fuel economy suffer.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and hassle out of the repair by programming this module specifically to your vehicle’s VIN. This ensures all factory settings and the latest GM software updates are loaded before it even ships. You get a part that communicates flawlessly with your XLR’s other systems, avoiding the costly and time-consuming trip to the dealership for programming.
A Technician’s Notebook: The Intermittent XLR Gremlin
A customer brought in his ’09 XLR with a complaint that stumped two other shops. The car would randomly lose power and the dash would light up, but by the time he got it towed, it would start and run fine. There were no stored codes. After checking all the usual suspects—grounds, wiring harnesses, fuel pressure—I focused on the ECM. On these vehicles, heat cycles can cause microscopic cracks in the circuit board. I connected a scan tool and monitored live data while applying heat to the ECM with a heat gun. Sure enough, the data streams went haywire. A new, properly programmed 2008-2009 XLR Engine Module fixed the issue permanently. It’s a classic example of how an ECM can fail without leaving obvious clues.
Common Signs of a Failing ECM
If you’re experiencing any of the following, a faulty engine computer could be the culprit. A failing module can often trigger a variety of diagnostic trouble codes (DTCs), making diagnosis tricky. Look out for these signs:
- ✔ Check Engine Light is illuminated (Common codes include P0601, P0606, U0100)
- ✔ Engine stalling or misfiring for no apparent reason
- ✔ Difficulty starting the engine or a complete no-start condition
- ✔ Noticeable decrease in fuel efficiency
- ✔ Poor acceleration or erratic engine performance
- ✔ Harsh or incorrect automatic transmission shifting
- ✔ Communication issues with diagnostic scan tools
A Straightforward Guide to Installation
Replacing the ECM on your Cadillac XLR is a manageable job for a confident DIYer. Our pre-programming service makes it a true plug-and-play process. Follow these general steps to get back on the road.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait about 15 minutes for the system capacitors to discharge.
- Locate the Module: On the 2008-2009 Cadillac XLR, the ECM is typically located in the engine bay, on the right-hand (passenger) side front engine compartment.
- Disconnect Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Never force them. Inspect the connectors for any corrosion or damage.
- Remove the Old ECM: Unbolt the mounting hardware that secures the old ECM to its bracket. Remove the old module from the vehicle.
- Install the New Module: Mount your new, pre-programmed 2008-2009 XLR Engine Module in the same location and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new ECM until they click into place. Reconnect the negative battery terminal.
- Final Steps: Some vehicles may require a security relearn procedure, which can often be done without special tools (e.g., turning the key to ‘ON’ for 10-15 minutes). Check your vehicle’s service manual for specific instructions. Start the engine and verify that the Check Engine Light is off and the car runs smoothly.
Verified Vehicle Compatibility
This ECM, part number 12630457, is a direct replacement for a wide range of General Motors vehicles. It is interchangeable with service numbers 12590032, 12602044, 12603530, 12605843, 12607096, and 19210737. Please verify your vehicle’s model and options below to ensure a perfect fit.
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
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential for us to program the ECM correctly. It allows us to load the exact software and calibrations specified by GM for your vehicle’s engine, transmission, and options. This ensures seamless integration and optimal performance right out of the box.
Is this part difficult to install?
For most DIYers with basic tools, this is a straightforward installation. Since we handle all the programming, you won’t need any special electronic tools. The main tasks are disconnecting the battery, swapping the physical module, and reconnecting everything. Please refer to our installation guide above.
Will this fix my Check Engine Light?
If the Check Engine Light is caused by an internal failure of the ECM (like codes P0601 or P0606), then yes, this part will resolve the issue. However, if the light is on due to a faulty sensor or other component, you will still need to fix that underlying problem.
What if my part number doesn’t match 12630457 exactly?
This module is a direct replacement for several service numbers, including 12590032, 12602044, 12603530, 12605843, 12607096, and 19210737. As long as your original module has one of these numbers, this part will work perfectly once programmed to your VIN.