Restore Peak Performance and Reliability to Your GM Vehicle
Is your Chevrolet Express or GMC Savana van running rough, stalling unexpectedly, or flashing a persistent Check Engine Light? These are classic signs of a failing Engine Control Module (ECM). As the brain of your vehicle’s engine, a faulty ECM can cause a cascade of frustrating and costly problems. This replacement ECM, part number 12633055, is the definitive solution to get your workhorse back on the road, operating with the precision and dependability you count on every day.
With over two decades of hands-on diagnostic experience, I’ve seen firsthand how a failing computer can cripple a perfectly good engine. From intermittent no-starts that leave you stranded to poor fuel economy that hurts your bottom line, the symptoms are often confusing. This module eliminates the guesswork. We take the hassle out of the repair by programming this 2010-2015 Express 3500 ECM with the latest GM-certified software, specifically matched to your vehicle’s VIN. This means no expensive trip to the dealership for programming—it arrives ready for installation.
From the Diagnostic Bay: The Case of the Unreliable Work Van
A local contractor brought in his 2012 Express 3500. The complaint was intermittent stalling at stoplights and a random P0606 (ECM/PCM Processor Fault) code that would come and go. He’d already replaced the throttle body and a few sensors with no luck. After verifying power and grounds to the ECM were solid, we knew the module itself was the culprit. Heat soak was causing an internal failure. We installed one of these pre-programmed ECMs, and the van was back in service the same afternoon—no more ghost codes, no more stalling. This is the kind of reliable, straightforward fix that keeps businesses running.
Is Your GM Truck or Van Showing These ECM Failure Signs?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs attention. Look out for:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Engine stalling or misfiring for no apparent reason
- ✔ Communication error codes, such as U0100 (Lost Communication with ECM/PCM)
- ✔ Internal processor failure codes like P0601, P0603, or P0606
- ✔ Noticeable decrease in fuel efficiency
- ✔ Problems with automatic transmission shifting
- ✔ Complete no-start condition where the engine cranks but won’t fire
Your Straightforward ECM Installation Guide
Installing your new 2010-2015 Express 3500 ECM is a manageable job for a DIYer or a quick task for a professional. Since we handle the programming, you can focus on the physical swap.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for capacitors to discharge.
- Locate the ECM: On Express and Savana vans, the ECM is typically found in the left-hand rear of the engine compartment. On trucks and SUVs, it’s usually on the left-hand front side.
- Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Never force them. Inspect connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New ECM: Mount the new, pre-programmed ECM securely onto the bracket.
- Reconnect Everything: Plug the electrical harnesses back into the new module until they click firmly 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. Turn the key to the ‘ON’ position for 10-15 minutes, then off, and repeat two more times before starting the engine. Consult your vehicle’s service information for specifics.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12633055 and 12633238. It fits a wide range of GM vehicles. Please verify your part number and application from the list below:
AVALANCHE 1500 (2010-2013)
CAMARO (2010-2015) – 6.2L, 7.0L
CAPRICE (2011-2017) – 6.0L
CORVETTE (2010-2013) – 6.2L, 7.0L
EXPRESS 1500 VAN (2010-2014) – 5.3L
EXPRESS 2500 VAN (2010-2015) – 4.8L, 6.0L
EXPRESS 3500 VAN (2010-2015) – 4.8L, 6.0L
SILVERADO 1500 PICKUP (2010-2013) – 4.8L, 5.3L, 6.2L
SILVERADO 2500/3500 PICKUP (2010) – 6.0L
SS CAPRICE (2014-2017)
SUBURBAN 1500 (2010-2014)
SUBURBAN 2500 (2010-2013)
TAHOE (2010-2014) – w/o hybrid
GMC:
SAVANA 1500 VAN (2010-2014) – 5.3L
SAVANA 2500 VAN (2010-2015) – 4.8L, 6.0L
SAVANA 3500 VAN (2010-2015) – 4.8L, 6.0L
SIERRA 1500 PICKUP (2010-2013) – 4.8L, 5.3L, 6.2L
SIERRA 2500/3500 PICKUP (2010) – 6.0L
SIERRA DENALI (2010) / DENALI 1500 (2011-2013)
YUKON (2010-2014) – w/o hybrid
YUKON XL 1500 (2010-2014)
YUKON XL 2500 (2010-2013)
Cadillac:
ESCALADE / ESV / EXT (2010-2014)
Frequently Asked Questions About This ECM
Do I need to program this ECM?
Do I need to program this ECM?
No. This is the biggest benefit we offer. We will program, or ‘flash,’ the ECM with the latest GM software using the VIN you provide during checkout. It will arrive ready to install, saving you a trip to the dealer.
What is a VIN and where do I find it?
The VIN is your vehicle’s unique 17-digit Vehicle Identification Number. You can find it on your driver’s side dashboard (viewable through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Will this fix my specific problem?
This module is a direct replacement for a faulty ECM. If your vehicle has been properly diagnosed with a failed ECM (e.g., codes like P0601, P0606, or U0100), then this part is the correct solution. It will not fix issues caused by other faulty components like sensors or wiring.
Is this the same as a PCM?
Yes, the terms ECM (Engine Control Module) and PCM (Powertrain Control Module) are often used interchangeably for these GM vehicles. This module controls both engine and, in many cases, transmission functions.