Restore Your Truck’s Performance with a VIN-Programmed PCM
Is your 1998 Chevy Blazer S10 or GMC Jimmy S15 running rough, stalling, or showing a persistent Check Engine Light? Before you start replacing sensors and chasing electrical gremlins, the problem might be the very brain of your vehicle: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless hours and dollars wasted on misdiagnosis when the PCM was the root cause. This module is the central command for your engine and transmission, and when it fails, it can create a cascade of confusing symptoms.
We make the repair process straightforward. This isn’t just a part in a box; it’s a complete solution. We professionally program this PCM to your truck’s specific Vehicle Identification Number (VIN) before it ships. This crucial step ensures it has the latest GM software updates, correcting potential factory issues and optimizing performance. You get a module that is truly plug-and-play, eliminating the need for an expensive trip to the dealership for programming.
A Technician’s Notebook: The S10 That Wouldn’t Shift Right
A customer brought in a ’98 Jimmy S15 with a complaint of harsh, erratic shifting and a check engine light. They had already replaced the vehicle speed sensor and a transmission solenoid based on a parts store scan, but the problem persisted. The codes were all over the place—a U-code for lost communication, a TPS code, and a transmission code. Instead of throwing more parts at it, we checked the PCM’s power and ground circuits, which were solid. Hooking up our professional scan tool, we noticed the data stream from the PCM was dropping out intermittently. That’s the classic sign of an internal failure. We installed a VIN-programmed PCM, performed the security relearn, and the truck drove perfectly. It was a reminder that a faulty PCM can send you on a wild goose chase, making other components look bad.
Common Signs of a Failing Powertrain Control Module
- ✔ Persistent Check Engine Light with various codes, especially internal module codes like P0601 or P0605.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Harsh or unpredictable automatic transmission shifting.
- ✔ A complete no-start condition where the engine cranks but won’t fire up.
- ✔ Noticeable decrease in fuel economy.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Failing an emissions or smog test.
A Straightforward Guide to Installation
Replacing the PCM on these S-series trucks is a job most DIYers can handle with basic tools. Just follow these steps carefully.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On the 1998 Blazer/Jimmy, the PCM is typically located in the engine compartment on the right-hand (passenger) side, often near the firewall or inner fender.
- Disconnect the Connectors: Carefully unlatch and remove the electrical harness connectors from the old module. These connectors have locking tabs, so be gentle to avoid breaking them. Note their color and position.
- 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 connectors back into the new PCM, ensuring they are fully seated and the locking tabs click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will likely need to perform a simple security relearn procedure (often called Passlock or VATS relearn) so the vehicle recognizes the new module. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Instructions are readily available online for your specific model.
Verified Vehicle Compatibility
This module, identified by part numbers 09366810, 16250279, or 09355699, is a direct replacement for a wide range of GM trucks and vans. Please verify your vehicle is on this list and that the ID on your original module matches. This part fits the following vehicles:
CHEVROLET 2500 PICKUP 98-99
CHEVROLET 3500 PICKUP 98-99
EXPRESS 1500/2500/3500 VAN 98
SUBURBAN 1500/2500 98-99
TAHOE 98-99
ASTRO 98-99
BLAZER S10/JIMMY S15 98 (w/o build date opt ZN4)
S10/S15/SONOMA 98 (4.3L, w/o build date opt ZN4)
GMC 1500 PICKUP 98-99
GMC 2500 PICKUP 98-99
GMC 3500 PICKUP 98-99
SAVANA 1500/2500/3500 VAN 98
YUKON 98-99
SAFARI (GMC) 98-99
ENVOY 98 (w/o build date opt ZN4)
BRAVADA 98 (4.3L, w/o build date opt ZN4)
ESCALADE 99
ISUZU HOMBRE 98 (4.3L, w/o extended build date opt ZN4)
Frequently Asked Questions
Why do you need my VIN?
Your VIN is essential. It allows us to load the exact, correct GM-certified software for your vehicle’s specific engine, transmission, and options. This ensures compatibility and proper function without a trip to the dealer.
Is this part difficult to install?
No, for most individuals with basic mechanical skills, this is a straightforward replacement. It involves disconnecting the battery, unplugging the old module, unbolting it, and then reversing the process. The only extra step is a simple security relearn procedure.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like code P0601), then yes, this will resolve the issue. However, you should always ensure other potential causes like faulty sensors or wiring have been ruled out for a complete diagnosis.
What is a security relearn?
It’s a simple procedure that syncs the new PCM with your vehicle’s anti-theft system. It usually involves turning the ignition key to the ‘ON’ position for about 10 minutes, then off, and then starting the vehicle. This tells the truck that the new module is authorized.
Are part numbers 16250279 and 09355699 the same as this one?
Yes, this module is a direct, compatible replacement for service numbers 16250279, 09366810, and 09355699. We program it to function perfectly for your vehicle regardless of which of these numbers was on your original part.