Restore Peak Performance to Your GM Truck or Van
If you’re dealing with a frustrating no-start condition, a persistent check engine light, or erratic engine behavior in your 1998-1999 GMC 1500, a failing Powertrain Control Module (PCM) is often the culprit. As the ‘brain’ of your vehicle, the PCM controls everything from fuel mixture and ignition timing to transmission shifting. When it falters, the symptoms can be widespread and confusing. This reliable, tested PCM is the direct solution, arriving pre-programmed with the latest GM software specifically for your vehicle’s VIN.
Is Your Truck Showing These Signs of a Failing PCM?
Over my 20+ years in the bay, I’ve seen how a bad PCM can mimic a dozen other problems. Before you start replacing sensors and other expensive parts, check if your vehicle is experiencing these classic symptoms of PCM failure:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or other P06xx codes.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling, rough idling, or hesitation during acceleration.
- ✔ A noticeable drop in fuel economy.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Communication errors with your scan tool.
A Technician’s Notebook: The Ghost in the Transmission
A customer brought in his ’99 Yukon complaining of erratic 1-2 shifting and a transmission that felt like it was slipping. He was convinced he needed a full transmission rebuild. After hooking up my scan tool, I noticed something odd—the PCM wasn’t commanding the shifts correctly, even though the transmission sensors were reading fine. Instead of a $2,500 transmission job, the fix was a properly programmed PCM. Heat and vibration had damaged the internal circuits controlling the transmission logic. This is a perfect example of why diagnosing the ‘brain’ first can save you thousands.
The Easiest Way to Replace Your Engine Computer
Forget expensive dealership visits and programming fees. We handle the complex part for you. By providing your vehicle’s VIN at checkout, you receive a module that is ready for installation. This 1998-1999 GMC 1500 PCM is a dependable, cost-effective solution to get your truck back to factory-spec operation.
A Straightforward Guide to Installation
With just a few basic hand tools, you can have this module installed in under 30 minutes. Follow these steps to get back on the road:
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- 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 unplug the electrical connectors from the old PCM. There are usually levers or tabs that need to be released.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket.
- Install the New PCM: Mount your replacement PCM and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Critical Final Step: Perform the GM Security Relearn Procedure (also known as Passlock relearn). This simple process syncs the new PCM to your vehicle’s anti-theft system and can be done without special tools. A quick search for ‘GM Passlock relearn’ will provide the easy key-on/key-off sequence.
Guaranteed Fitment for Your GM Vehicle
This module is a direct replacement for service number 16258815 and is also compatible with modules identified by part numbers 09355699, 16266645, 16250279, and 9366810. It is confirmed to fit the following vehicles (verify your engine and options):
- ✔ 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- ✔ 1998-1999 Chevrolet & GMC Suburban (Gasoline)
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana Vans (1500/2500/3500, Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Oldsmobile Bravada, GMC Envoy, Chevrolet Blazer S10, GMC Jimmy S15 (4.3L)
- ✔ 1998 Chevrolet S10 & GMC Sonoma (4.3L)
- ✔ 1998 Isuzu Hombre (4.3L)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to load the exact, correct GM factory software for your truck’s specific engine, transmission, and options. This ensures perfect compatibility and performance, just like a new module from the dealer.
Is this part difficult to install?
Not at all. It’s a simple plug-and-play physical installation. The only required procedure afterward is the Security Relearn, which involves a sequence of turning the key on and off and takes about 30 minutes to complete without any special tools.
You mentioned this part is used. Is it reliable?
Yes. Every module we sell is sourced from a salvaged vehicle and thoroughly inspected and tested to ensure it is fully functional. We then program it with fresh software. This provides a reliable, working part at a fraction of the cost of a new one.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like code P0601), then yes, this will resolve the issue. However, you should always ensure that the codes are not being caused by a faulty sensor or wiring problem elsewhere on the vehicle.
What if I have a different part number on my original computer?
This module replaces several part numbers. As long as your vehicle is on the compatibility list and your original module has one of the listed interchangeable part numbers (like 09355699 or 16266645), this part will work perfectly once programmed to your VIN.