Restore Your Truck’s Core Performance and Reliability
Is your trusty GMC or Chevy truck plagued by frustrating issues like a persistent check engine light, erratic shifting, a no-start condition, or poor fuel economy? These are classic signs that the brain of your vehicle—the Powertrain Control Module (PCM)—is failing. After 20 years in the garage, I’ve seen how a faulty PCM can sideline even the most dependable workhorses. This isn’t just a part; it’s the central command for your engine and transmission, and when it falters, everything suffers. Don’t let a complex-sounding problem keep you off the road. We offer a straightforward, reliable solution.
This is a tested, used OEM 1998-1999 GMC 3500 PCM that provides a dependable and cost-effective fix. The critical advantage we offer is our professional programming service. Before this module ships, we flash it with the latest official GM software updates, specifically calibrated to your vehicle’s VIN. This means it arrives ready for installation, saving you the time, expense, and hassle of a dealership visit for programming. It’s the most direct path to getting your truck running right again.
Is Your Truck Showing These Telltale Signs?
- ✔ Persistent Check Engine Light with codes like P0601, P0602, or P0606.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel mileage.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stalling, sputtering, or rough idling.
- ✔ Communication errors with diagnostic scan tools.
From the Diagnostic Bay: The Case of the Intermittent Workhorse
A local contractor brought in his ’99 Chevy 3500 with a problem that was driving him nuts. It would start and run perfectly for days, then suddenly refuse to start, leaving his crew stranded. There were no consistent codes, just a frustrating intermittent failure. After checking the usual suspects—fuel pressure, spark, battery—we hooked up our scope to the PCM’s power and ground circuits. We found that the internal voltage regulation within the original PCM was unstable, occasionally dropping out and preventing the fuel injectors from firing. Swapping in a VIN-programmed module like this one provided a permanent fix, getting his essential work truck back in service reliably. These symptoms can be tricky, but often the PCM is the root cause.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle in their own driveway. Follow these steps for a smooth installation.
- 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 Connectors: Carefully unlatch and remove the electrical harness connectors from the old module. These connectors have locking tabs; be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you’ll need it for the new module.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Firmly plug the harness connectors into the new PCM until they click into place. Reconnect your battery’s negative terminal.
- Perform Security Relearn: Your vehicle may require a simple security relearn procedure to recognize the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for the exact procedure for your model.
Verified Vehicle Compatibility
This module is a direct replacement for service number 16250279 and will also interchange with part numbers 09355699, 16266645, 16258815, and 09366810. It is confirmed to fit the following gasoline-engine vehicles with matching ID 9355699:
- 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickups
- 1998-1999 Chevrolet & GMC Suburban 1500/2500
- 1998-1999 Chevrolet Tahoe & GMC Yukon
- 1999 Cadillac Escalade
- 1998-1999 Chevrolet Express & GMC Savana 1500/2500/3500 Vans
- 1998 Chevrolet Astro & GMC Safari
- 1998 Chevrolet S10, GMC Sonoma, Isuzu Hombre (4.3L V6)
- 1998 Chevrolet Blazer & GMC Jimmy (4.3L V6)
- 1998 Oldsmobile Bravada & GMC Envoy (4.3L V6)
Note: It is crucial to match your original part number or the ID number 9355699 to ensure compatibility. If you are unsure, please contact us with your VIN.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the module with the exact software calibration and updates specified by GM for your truck’s engine, transmission, and options. This ensures seamless integration and optimal performance.
Is this part difficult to install?
No, this is a direct-fit replacement. The physical installation involves basic hand tools. The only additional step may be a simple security relearn procedure, which does not require special tools and can be found in your owner’s manual or online.
What does ‘used’ mean for this part?
This is a genuine OEM module sourced from a salvaged vehicle. We thoroughly inspect and test each unit to ensure it’s fully functional before programming and shipping it to you. It’s a reliable alternative to a costly new part.
Will I have to get this programmed at a dealership?
No. The main benefit of our service is that we handle all the programming for you. The module arrives ready to be installed, saving you that extra step and expense.
What if my original part number is different?
This module replaces several part numbers, including 09355699 and 16266645. As long as your vehicle is on the compatibility list and your original module carries one of the listed interchangeable part numbers, this will be the correct fit.