Is Your GM Truck or Van Running Rough? The PCM Might Be the Culprit.
If you’re dealing with a frustrating no-start condition, intermittent stalling, a persistent check engine light, or harsh shifting in your 1998-1999 GMC 3500, the brain of your vehicleโthe Powertrain Control Module (PCM)โis a likely suspect. Over two decades of service, these modules can fail due to heat cycles, vibration, and internal component aging. In my shop, I’ve seen countless GMT400-platform vehicles with symptoms that owners chased for weeks, replacing sensors and parts, when the core issue was a faulty PCM.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We are offering a reliable, used OEM PCM that has been sourced from a salvaged vehicle and is ready for a new life in your truck. The real value is in our programming service: we flash this computer with the latest official GM software, tailored specifically to your vehicle using the VIN you provide. This ensures that your engine, transmission, and all related systems communicate perfectly, just as they did from the factory.
Why is this the Right 1998-1999 GMC 3500 PCM for You?
Getting your workhorse truck back on the road shouldn’t be a complicated ordeal. This module eliminates the guesswork and the expensive trip to a dealership for programming.
- โ VIN-Programmed Convenience: We handle the complex part. Provide your VIN at checkout, and we’ll program the module. It arrives at your door ready to be installed.
- โ Latest GM Software Updates: Your PCM will be loaded with the most current calibrations from General Motors, which can resolve common driveability issues and improve performance.
- โ Broad Compatibility: While perfect for your GMC 3500, this module (ID 9355699) is a direct replacement for a wide range of GM trucks and vans from that era. See our full fitment list below.
- โ Cost-Effective Repair: Avoid the high cost of a new module and the separate programming fees charged by dealerships or specialty shops.
Expert Pro Tip from a 20-Year Technician
Before you install your new PCM, take five minutes to inspect and clean your main ground connections. On these GM trucks, the primary engine-to-frame ground strap and the negative battery cable connections can corrode over time. A poor ground can cause erratic voltage, mimicking the exact symptoms of a failed PCM. A quick cleaning with a wire brush can prevent a misdiagnosis and ensure your new module functions perfectly from the start.
Plug-and-Play Installation: No Dealer Visit Required
You can perform this repair right in your driveway with basic hand tools. Follow these simple steps to get your truck running smoothly again.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998-1999 GM trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Old Module: Carefully unplug the wiring harness connectors. These usually have a locking tab or lever that needs to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed PCM into place. Securely reconnect the wiring harnesses, ensuring they click and lock into position.
- Reconnect the Battery: Attach the negative battery terminal. Your vehicle is now ready to start. The computer will perform a self-learning process over the first few drive cycles.
Will This Fit My Vehicle?
This PCM is a direct replacement for units with service number 16258815 or identifier 9355699. It is compatible with the following part numbers: 09355699, 16266645, 16250279, 09366810, 9366810. Please verify the part number on your original module to ensure a perfect match. This unit fits a massive range of Chevrolet, GMC, Cadillac, and Isuzu models, including the Tahoe, Suburban, Express, Savana, S10/Sonoma, and many more, as detailed in the comprehensive fitment chart.