Restore Your GM Truck’s Performance and Reliability
Is your 1998 Chevy Blazer, GMC Jimmy, or S10 Sonoma giving you headaches? If you’re dealing with a persistent check engine light, rough idle, stalling, or unpredictable transmission shifting, a failing Powertrain Control Module (PCM) is often the culprit. As the brain of your vehicle’s engine and transmission, when the PCM starts to fail, it can cause a cascade of frustrating and hard-to-diagnose problems. This replacement module is the definitive solution to get your trusted truck back on the road and running smoothly.
We take the guesswork and hassle out of the repair. Unlike sourcing a part from a junkyard that may have the same issues or require expensive dealer intervention, this module arrives at your door programmed specifically for your vehicle. Simply provide us with your Vehicle Identification Number (VIN) during checkout, and our technicians will flash the unit with the latest factory software from GM. This ensures seamless communication between all your vehicle’s systems, restoring original performance and fuel efficiency.
Is Your Blazer or Jimmy Showing These Symptoms?
A faulty PCM can manifest in many ways. From my 20+ years of experience in the service bay, here are the most common signs that point to a failing module in these GM vehicles:
- ✔ Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ Engine cranks but won’t start (no-start condition).
- ✔ Rough or erratic engine idle.
- ✔ Unexplained stalling or hesitation during acceleration.
- ✔ Poor fuel economy.
- ✔ Harsh or incorrect transmission shifting.
- ✔ Failure to pass an emissions or smog test.
From the Diagnostic Bay
I remember a 1998 GMC Jimmy with the 4.3L V6 that came into my shop. The owner was at his wit’s end. He’d replaced the fuel pump, spark plugs, and wires, but the truck still had an intermittent stalling issue that no one could pinpoint. It would run fine for days, then suddenly die at a stoplight. After hooking up my scan tool and monitoring live data, I noticed the fuel trim values would suddenly go haywire right before a stall. All sensor inputs looked good. On a hunch, I gently tapped on the PCM casing with a screwdriver handle, and the engine immediately stumbled. That confirmed it—an internal fault in the module. We installed a VIN-programmed PCM just like this one, and the Jimmy ran perfectly. It’s a classic failure mode for these units after decades of heat cycles and vibration.
A Straightforward Guide to Installation
For the confident DIYer, replacing the PCM on these vehicles is a manageable job. You don’t need a full mechanic’s tool chest, just some basic hand tools and patience.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system’s capacitors to discharge.
- Locate the PCM: On the 1998 Blazer, Jimmy, and S-series trucks, the PCM is typically located in the engine bay, on the passenger side (RH side) near the firewall or inner fender.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old module. There are usually several multi-pin connectors. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few small bolts.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Plug the electrical harnesses back into the new module. Ensure they click into place and are fully seated. Reconnect your vehicle’s negative battery terminal.
- Final Steps: In some cases, a security relearn procedure (often called a Passlock relearn) may be necessary. This can typically be done without special tools by cycling the ignition key. Your vehicle’s service manual will have the specific steps.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. Please verify your original part number or contact us with your VIN to confirm compatibility. This part fits the following vehicles:
- ✔ 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickup (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban & Tahoe (Gasoline)
- ✔ 1998-1999 GMC Yukon (Gasoline)
- ✔ 1999 Cadillac Escalade
- ✔ 1998 Chevrolet Blazer S10 / GMC Jimmy S15 / Oldsmobile Bravada (4.3L V6, w/o build date opt ZN4)
- ✔ 1998 GMC Envoy (w/o build date opt ZN4)
- ✔ 1998 Chevrolet S10 / GMC Sonoma (4.3L V6, w/o build date opt ZN4)
- ✔ 1998 Isuzu Hombre (4.3L V6, w/o extended build date opt ZN4)
- ✔ 1998-1999 Chevrolet Astro / GMC Safari
- ✔ 1998 Chevrolet Express Van 1500/2500/3500 (Gasoline)
- ✔ 1998 GMC Savana Van 1500/2500/3500 (Gasoline)
Frequently Asked Questions
What does ‘VIN Programmed’ mean?
It means we load your vehicle’s unique 17-digit VIN into the module before we ship it. This process installs the correct software and calibrations for your truck’s specific engine, transmission, and options, making it a true plug-and-play solution.
How do I provide my VIN?
After you complete your purchase, you will need to send us a message with your vehicle’s VIN. We cannot ship the module until we receive this information.
Will I need to do anything else after installing this 1998 Blazer S10 PCM?
In most cases, the installation is straightforward. However, some GM vehicles of this era may require a security relearn procedure to sync the module with your anti-theft system. This procedure can usually be performed by the owner and does not require a scan tool.
How can I be sure this is the correct part for my truck?
The best way is to match the part number from your original module to one of the compatible numbers listed (16250279, 09366810, 09355699). If you are unsure, please send us your VIN, and we will happily verify the fitment for you.
What happens if I install it without programming?
An unprogrammed module will not work correctly. It may cause a no-start condition, enable the anti-theft system, or result in poor engine and transmission performance because the calibrations will be wrong for your vehicle. Our pre-programming service eliminates this problem.