Restore Your GM Truck’s Performance and Reliability
If you’re dealing with a frustrating check engine light, poor fuel mileage, erratic shifting, or a no-start condition on your 1998 Chevy Blazer, GMC Jimmy, or another compatible GM vehicle, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience under the hood, I’ve seen countless vehicles sidelined by faulty electronics. The PCM is the brain of your vehicle, and when it starts to go, it can create a cascade of confusing and intermittent problems that are a nightmare to diagnose.
This isn’t just a replacement part; it’s a complete solution. We take the guesswork and hassle out of the repair by pre-programming this module specifically for your vehicle using your VIN. This means it arrives at your door with the latest GM factory software updates already installed, addressing common driveability issues and ensuring optimal performance. You get a reliable, plug-and-play fix without the expensive trip to the dealership for programming.
From the Diagnostic Bay: The Ghost in the Machine
I remember a customer bringing in his ’98 GMC Sonoma with an intermittent no-start that had three other shops stumped. It would run fine for weeks, then refuse to start for an hour, only to fire right up again. No consistent codes, just frustration. After checking all the usual suspects—fuel pressure, spark, crank sensor—we hooked up a scope to the PCM outputs. We found that during the no-start events, the injector drivers inside the PCM were intermittently failing. It was a classic internal module failure caused by years of heat cycles. We installed a VIN-programmed PCM, and the truck never had the issue again. It’s a perfect example of how a solid, correctly programmed module is the only true fix for these phantom problems.
Is Your Truck Showing These Signs of PCM Failure?
A failing computer can manifest in many ways. If you’re experiencing any of the following, it’s a strong indicator that your PCM needs attention. This is especially true if you’ve already replaced sensors without success.
- ✔ Persistent Check Engine Light (CEL)
- ✔ Stored diagnostic trouble codes (DTCs) like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault)
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Harsh or erratic automatic transmission shifting
- ✔ A sudden, unexplained drop in fuel economy
- ✔ The vehicle will not start, but the battery and starter are good
- ✔ Failure to pass an emissions or smog test
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle with basic tools. Our pre-programmed module makes it even simpler. Follow these general steps to get your vehicle back in top shape.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most 1998 Blazer/Jimmy/S10 models, the PCM is located in the engine bay on the passenger side (RH side) firewall or inner fender. On full-size trucks and vans, it’s typically on the driver’s side (LH side) near the battery.
- Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old module. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM into the bracket and securely bolt it in place.
- Reconnect Everything: Firmly plug the harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In some cases, you may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for the exact procedure. After this, your vehicle should start and run correctly with its new brain.
Will This Fit My Vehicle?
This module is a direct replacement for original equipment part numbers 09355699, 16250279, and 09366810. It is guaranteed to fit the following makes and models. Please verify your vehicle and engine options below.
Note: This PCM fits a wide range of GM trucks, SUVs, and vans from 1998-1999. Please match your vehicle and original part number for guaranteed compatibility.
- 1998 Chevrolet/GMC S10, S15, Sonoma, Blazer, Jimmy, Bravada, Envoy, Isuzu Hombre (4.3L V6, w/o build date opt ZN4)
- 1998-1999 Chevrolet/GMC C/K 1500, 2500, 3500 Pickups (Gasoline Engines: 5.0L, 5.7L)
- 1998-1999 Chevrolet/GMC Suburban, Tahoe, Yukon (Gasoline Engines)
- 1998-1999 Chevrolet Express / GMC Savana Vans (1500, 2500, 3500, Gasoline Engines)
- 1998-1999 Chevrolet Astro / GMC Safari Vans (4.3L V6)
- 1999 Cadillac Escalade (5.7L)
Frequently Asked Questions
What is the process after I purchase?
It’s simple. After you complete your purchase, you will need to send us your vehicle’s 17-digit Vehicle Identification Number (VIN). We use this to load the correct, updated GM software onto the module before we ship it to you.
Is this part difficult to install?
No, this is a plug-and-play part for most DIY mechanics. Since we handle the programming, you just need basic hand tools to swap the physical module. No special computer equipment is required.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the original PCM (common codes include P0601-P0606), then yes, this part is the correct fix. It’s always best to have the codes read to confirm the diagnosis before ordering.
Do I need to do anything after installation?
In many cases, the vehicle will start and run perfectly after installation. Some vehicles may require a simple security relearn procedure, which involves leaving the key in the ‘on’ position for about 10 minutes. This allows the PCM to sync with your vehicle’s anti-theft system.
Is there a core charge?
No, there is no core charge for this part. You do not need to send your old, faulty module back to us.
What if I have the wrong part number?
This module replaces several part numbers, including 16250279 and 09366810. As long as your vehicle is on the compatibility list and you provide a valid VIN, we will ensure the programming is a perfect match for your application.