Restore Peak Performance to Your GM Workhorse
Is your trusty GMC Savana or Chevy Express van suddenly running rough, stalling, or refusing to start? As a mechanic with over two decades of experience, I’ve seen these symptoms countless times. Often, the culprit isn’t a bad sensor or fuel pump, but the very brain of the vehicle: the Powertrain Control Module (PCM). When the PCM fails, it can create a cascade of frustrating and hard-to-diagnose issues. This isn’t just an inconvenience; for a work van, downtime means lost money.
We offer a straightforward, reliable solution. This is a tested, used factory PCM that we program specifically for your vehicle using your VIN. This means it arrives at your door with the latest GM software updates already installed, tailored to your exact engine, transmission, and options. You get a part that’s ready to install, saving you the time, expense, and hassle of a trip to the dealership for programming.
Case Study: The Misleading No-Start
A few months back, a 1999 Express 2500 was towed into my shop. It had an intermittent no-start condition that had two other shops stumped. They had replaced the fuel pump and the crank sensor, but the problem persisted. The driver was at his wit’s end. My diagnostic process started with the basics, but everything checked out. On a hunch, I connected my scan tool and monitored data PIDs from the PCM during cranking. I noticed the injector pulse command was dropping out randomly. It wasn’t a wiring issue; the PCM itself was failing internally under load. We installed one of our VIN-programmed PCMs, performed the security relearn, and the van fired up instantly. It’s been on the road daily ever since. This simple swap saved the owner from chasing phantom problems and spending hundreds more on unnecessary parts.
Common Signs of a Failing PCM
If your vehicle is experiencing any of the following, a faulty PCM could be the root cause. A failing module can often trigger diagnostic trouble codes (DTCs) like P0601, P0605, or various communication errors.
- ✔ Unexplained Check Engine Light
- ✔ Engine stalling or misfiring
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to start or intermittent starting problems
- ✔ Noticeable decrease in fuel economy
- ✔ Vehicle failing emissions testing
- ✔ Communication issues with diagnostic scan tools
A Straightforward Guide to Installation
Replacing the PCM in these GM vans and trucks is a job most DIYers can handle with basic tools. The key is taking your time and following the proper procedure, especially the security relearn at the end.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old PCM. Inspect the terminals for any corrosion or damage before proceeding.
- Swap the Module: Unbolt the old PCM from its mounting bracket and install the new, programmed module in its place.
- Reconnect Everything: Securely plug the electrical harnesses into the new PCM. You should hear a click as they lock in place. Reconnect the negative battery terminal.
- Perform Security Relearn (CRITICAL): This step is essential. The Passlock or Passkey system needs to sync with the new PCM. The most common method is the “10-Minute Relearn Procedure.” Turn the key to the “ON” position (don’t start it), wait for the “Security” light to turn off (approx. 10 minutes), turn the key off for 5 seconds, and repeat this process two more times. After the third cycle, the vehicle should start and run.
Will This Fit My Truck or Van?
This PCM is a direct replacement for a wide range of popular GM vehicles from the late 1990s that use service number 09366810 or interchange part number ID 9355699. Please verify the part number on your original module to ensure compatibility. This unit fits, but is not limited to, the following vehicles:
- Chevrolet Express & GMC Savana Vans (1500, 2500, 3500): 1998-1999
- Chevrolet & GMC Pickups (1500, 2500, 3500): 1998-1999
- Chevrolet Suburban & GMC Yukon XL (1500, 2500): 1998-1999
- Chevrolet Tahoe & GMC Yukon: 1998-1999
- Cadillac Escalade: 1999
- Chevrolet Astro & GMC Safari: 1998
- Chevrolet S10, GMC Sonoma, Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada, Isuzu Hombre: 1998 (4.3L V6 models)
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations your vehicle had when it left the factory, including any official updates released by GM. This ensures perfect compatibility and performance.
Is this part difficult to install?
No, the physical installation is straightforward for anyone with basic mechanical skills. The most important part is performing the security relearn procedure after installation, which requires no special tools. We’ve outlined the steps above.
Is this a new part?
This is a high-quality, tested used PCM recovered from a salvaged vehicle. Each unit is inspected and verified to be fully functional before being programmed and shipped. This provides a reliable and cost-effective alternative to a new dealership part.
Will I need to do anything else after installation?
After installing the PCM and performing the security relearn, you may need to have a professional with a high-end scan tool perform a Crankshaft Variation Relearn (also known as a CASE relearn). While many vehicles run fine without it, this procedure helps the PCM fine-tune its misfire detection for maximum accuracy.
What if I have a different part number?
This module replaces several part numbers, including 09355699, 16266645, 16250279, and 16258815. If your part number is on this list, our module will work perfectly for your vehicle.