Is Your Work Van Down? Get Back on the Road Fast.
For a business owner, a 2018 GMC Savana 3500 that won’t start or runs poorly isn’t just an inconvenienceโit’s a direct hit to your bottom line. As a technician with over two decades of experience, I’ve seen firsthand how a failing Engine Control Module (ECM) can bring a reliable workhorse to a dead stop. You’re likely experiencing frustrating, hard-to-diagnose issues that are costing you time and money.
Common Symptoms of a Failing GM ECM:
- โ Unexplained Check Engine Light (CEL) with various communication or performance codes.
- โ Engine cranks but refuses to start.
- โ Severe performance problems, like stalling, hesitation, or rough idling.
- โ Poor fuel economy and erratic transmission shifting.
- โ Communication loss with other vehicle modules, causing multiple warning lights.
From the Shop Floor: A Real-World Diagnosis
“A customer’s 2018 Savana 3500 came in last week with intermittent stalling and a no-start condition that left his crew stranded. The previous shop replaced the fuel pump, but the problem persisted. After hooking up my scan tool, I noticed a complete loss of communication with the ECM at random intervals. It wasn’t a wiring issueโthe module itself was failing internally from heat cycles and vibration, a common failure point I’ve seen on hundreds of these work vans. We replaced the ECM with a correctly programmed unit, performed the security relearn, and the van was back in service the same day, running perfectly.”
The Direct Solution: A VIN-Programmed ECM
This isn’t just a replacement part; it’s a complete solution. We are providing a genuine GM Engine Control Module, part number 12704475, that is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN). This ensures all factory calibrations for your engine and transmission are loaded and correct, eliminating the guesswork and the need for an expensive trip to the dealership for initial programming.
Easy Installation for Your 2018 Savana 3500 ECM
Replacing the ECM on your Savana is straightforward. It’s located in the left-hand rear of the engine compartment. Following these steps will ensure a smooth installation.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait 10-15 minutes for all modules to power down completely.
- Locate the ECM: Find the module on the driver’s side, towards the back of the engine bay.
- Disconnect Connectors: Carefully release the locking tabs and unplug the electrical connectors from the old ECM. Inspect the pins and harness for any corrosion or damage.
- Swap the Module: Unbolt and remove the old ECM. Mount the new module securely in its place.
- Reconnect Everything: Plug the electrical connectors firmly into your new ECM until they click. Reconnect the negative battery terminal.
IMPORTANT POST-INSTALLATION NOTICE
After installation, you must perform a Vehicle Theft Deterrent System Relearn. If the van does not start, this is the reason. This procedure is required to sync the new ECM with your vehicle’s security system. It must be done using a professional tool with access to GM’s Tis2web or Techline Connect service. Other procedures, such as a Crankshaft Variation Relearn or injector flow rate programming, may also be necessary depending on your vehicle’s specific configuration. This is the responsibility of the installer.
Guaranteed Compatibility
This module is a direct replacement for part number 12704475 and is also interchangeable with the following part numbers:
- โ 12692069
- โ 12680656
- โ 12686383
- โ 12688528
This ECM fits a wide range of 2018-2019 GM vehicles, including the Chevrolet Corvette, Silverado 1500, Express Van, Suburban, Tahoe, GMC Sierra 1500, Savana Van, Yukon, Cadillac Escalade, and XTS. Please verify your part number or contact us with your VIN to confirm fitment.