Restore Your GM Truck’s Performance with a VIN-Programmed PCM
Is your 1998 Chevrolet Blazer S10, GMC Jimmy, or another GM truck from that era giving you headaches? If you’re dealing with a persistent check engine light, erratic engine behavior, or a frustrating no-start condition, a failing Powertrain Control Module (PCM) is a very likely culprit. As a mechanic with over two decades of experience, I’ve seen how a faulty PCM can sideline an otherwise reliable vehicle. This isn’t just a part; it’s the brain of your engine, and when it fails, nothing works right. That’s why we offer this fully tested, used OEM PCM, programmed specifically to your vehicle’s VIN before it ships.
Forget the hassle and expense of a dealership visit. We take a quality, salvaged PCM and flash it with the latest official GM software updates for your exact vehicle. All you need to do is provide your Vehicle Identification Number (VIN) after purchase. This ensures perfect communication between the engine, transmission, and other onboard systems, restoring the smooth operation and fuel efficiency you expect. This is the most direct and reliable way to solve complex electronic issues and get your truck back on the road with confidence.
Case Study: The Phantom No-Start
I once had a 1998 GMC Jimmy S15 in my bay that would randomly refuse to start, but only after it was fully warmed up. The owner had already replaced the battery, starter, and fuel pump. No codes were stored. On a hunch, I monitored sensor data and noticed the PCM would stop communicating when the engine bay got hot. After letting it cool, it would start right up. We swapped in a VIN-programmed PCM like this one, and the problem was solved instantly. These modules can develop internal cracks on the circuit board that only separate and cause issues at specific temperatures, making them incredibly tricky to diagnose without experience.
Common Signs of a Failing PCM
If your vehicle is experiencing any of the following, a faulty PCM could be the root cause. Replacing your module can resolve these issues and prevent further damage to related components like the transmission or catalytic converter.
- ✔ Check Engine Light is on with codes like P0601, P0605, or other internal processor faults.
- ✔ The engine cranks but refuses to start.
- ✔ Stalling, stumbling, or rough idling for no apparent reason.
- ✔ A noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with your scan tool.
- ✔ Intermittent issues that seem to have no logical cause.
A Straightforward Guide to Installation
Installing your new PCM is a job most DIYers can handle in under an hour with basic hand tools. Following these steps will ensure a smooth process. Note: After installation, you will need to perform a security relearn procedure (often called VATS or Passlock) which does not require a scan tool. We can provide instructions for this simple procedure.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998 Blazer S10/Jimmy S15 models, the PCM is located in the engine compartment, typically on the passenger-side (RH) firewall or inner fender. For vans and full-size trucks, it’s often on the driver’s side (LH).
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New PCM: Mount your new, pre-programmed PCM into the bracket and securely re-attach the wiring harness connectors.
- Reconnect and Relearn: Reconnect the negative battery terminal. Now, perform the security relearn procedure to sync the new PCM with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This PCM, identified by service ID 9355699, is a direct replacement for part numbers 16250279, 09355699, 16266645, 16258815, and more. It is guaranteed to fit the following vehicles. Please match your service ID number to ensure compatibility.
- ✔ 1998-1999 Chevrolet & GMC C/K 1500, 2500, 3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban & GMC Suburban (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500, 2500, 3500 Vans (Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Oldsmobile Bravada
- ✔ 1998 GMC Envoy
- ✔ 1998 Chevrolet Blazer S10 & GMC Jimmy S15 (4.3L)
- ✔ 1998 Chevrolet S10 & GMC Sonoma (4.3L)
- ✔ 1998 Isuzu Hombre (4.3L)
Frequently Asked Questions
Do I need to do anything after I buy it?
Yes. After you complete your purchase, you must send us your 17-digit VIN. We cannot program and ship the module without it. This ensures it works correctly with your vehicle’s specific options.
Is this part new?
No, this is a high-quality, tested used part that has been sourced from a salvaged vehicle. Each unit is inspected and programmed with the latest GM software to ensure reliability.
Will I need a mechanic to install this?
While professional installation is always an option, this part is designed for a straightforward swap. The main task after physical installation is a security relearn procedure, which is a simple key-on/key-off process that you can do yourself in about 30 minutes.
What if my part number is slightly different?
This module, with service ID 9355699, directly replaces several part numbers including 16250279, 16266645, and 09355699. As long as your vehicle is on the compatibility list and your original module has one of the listed part numbers, this will work perfectly.