Is your 1998 Chevy S10, GMC Sonoma, or another compatible GM truck running rough, stalling, or throwing confusing check engine light codes? A failing Powertrain Control Module (PCM) is often the culprit behind these frustrating and hard-to-diagnose issues. The PCM is the brain of your vehicle, controlling everything from fuel mixture and ignition timing to transmission shift points. When it fails, performance suffers, and you can be left stranded. This replacement PCM, part number 09355699, is the definitive solution to restore your truck’s reliability and performance.
We take the guesswork and hassle out of the repair process. Unlike a generic module from a parts store or salvage yard, this unit comes pre-programmed specifically for your truck. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and our technicians will flash the module with the latest GM-certified software updates. This ensures perfect communication with all your vehicle’s systems, a seamless installation, and optimal engine performance right out of the box.
Signs Your Powertrain Control Module is Failing
- ✔ Check Engine Light is on with codes related to sensors, emissions, or internal module failure.
- ✔ Your engine misfires, runs rough, or stalls intermittently.
- ✔ You experience a sudden, unexplained drop in fuel economy.
- ✔ The automatic transmission shifts harshly, late, or not at all.
- ✔ The vehicle fails to start, even with a good battery and starter.
- ✔ You’re experiencing issues with the anti-theft system (Passlock).
From the Diagnostic Bay
We had a 1998 GMC Jimmy with the 4.3L V6 come in on a tow truck. The customer said it would crank but never start, and he had already replaced the fuel pump and ignition coil. The security light was flashing, a classic sign of a Passlock system issue. After confirming fuel pressure and spark were present, we scanned the computer and found no communication with the PCM. A quick check of the PCM’s power and ground wires confirmed they were good. The module itself had failed internally, preventing the Passlock system from getting the ‘all clear’ signal. We installed a VIN-programmed PCM just like this one, performed the 10-minute security relearn procedure, and the Jimmy fired right up and ran perfectly. It saved the customer from chasing down more phantom electrical gremlins.
Your Direct-Fit 1998 S10 PCM Solution
This module is a direct replacement for a wide range of 1998-1999 GM trucks, vans, and SUVs, including the Chevy S10, GMC Sonoma, Blazer, Jimmy, and many full-size pickups. It replaces original part numbers 16250279, 09366810, and 09355699. By providing your VIN, you guarantee that you receive a module correctly configured for your engine, transmission, and specific options. This eliminates the need for expensive trips to the dealership for programming, making it a cost-effective and straightforward DIY repair.
Installation is simple: disconnect the battery, unplug the electrical connectors from your old PCM, unbolt it from its bracket, and install the new one in its place. After reconnecting the battery, you may need to perform a simple security relearn procedure, which can typically be done without any special tools. Get your truck back on the road with confidence by ordering this pre-programmed 1998 S10 PCM today.
Frequently Asked Questions
Do I need to program this module?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s VIN when you place your order, and the module will arrive ready to install with the latest GM software for your specific vehicle.
What is the difference between a PCM, ECM, and ECU?
These terms are often used interchangeably. ECU (Electronic Control Unit) is a general term. ECM (Engine Control Module) specifically controls engine functions. PCM (Powertrain Control Module) is the most common term for modern vehicles, as it controls both the engine and the transmission functions in one unit.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this part will resolve the issue. However, it’s always recommended to have the codes professionally scanned to ensure the problem isn’t a separate failed sensor or component that the PCM is correctly identifying.
What is a security relearn procedure?
Many GM vehicles of this era use a Passlock anti-theft system that is tied to the PCM. After installing a new module, you may need to ‘relearn’ the key to the system. This is a simple procedure that usually involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’, and repeating a couple of times. Instructions are readily available online for your specific model.
Where is the PCM located on my 1998 S10 or Sonoma?
On the 1998 S10, S15, Sonoma, Blazer, and Jimmy, the PCM (or ECM) is typically located in the engine compartment on the right-hand (passenger) side, often near the firewall or inner fender.