Is Your GM Truck or Van Running Rough?
If you’re dealing with frustrating issues like a persistent check engine light, unexplained stalling, erratic shifting, or a complete no-start condition on your 1998-1999 GM vehicle, a failing Powertrain Control Module (PCM) is a very likely culprit. After 20+ years on the road, the original electronic components inside these modules can break down from heat cycles and vibration, leading to problems that can be impossible to diagnose without swapping the part. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded.
From My Shop to Your Driveway: A Real-World Scenario
“A customer’s 1999 Chevy Tahoe came in last week with these exact symptomsโit would randomly die at stoplights and had a transmission that shifted hard from first to second. He’d already spent a fortune on a new fuel pump and transmission service with no luck. We hooked up our professional scanner and saw erratic data from multiple sensors, but the sensors themselves tested fine. This pointed directly to the processor in the PCM. We installed one of these pre-programmed modules, and it was like driving a new truck. All the issues were gone instantly. This is a fix I’ve performed hundreds of times on these GMT400 platform vehicles.”
The Direct Solution: A VIN-Programmed 1998-1999 GMC 1500 PCM
Forget the high costs and scheduling hassles of a dealership. We offer a reliable, tested, and ready-to-install PCM for your vehicle. This is a genuine used GM module, sourced from a salvaged vehicle, that has been meticulously inspected. The critical difference is our service: we flash the module with the latest official GM software updates, specifically programmed to your vehicle’s VIN. This ensures seamless communication with your engine, transmission, and anti-theft system right out of the box.
- โ VIN-Specific Programming: Arrives flashed with the newest GM calibration for your exact vehicle.
- โ Solves Common Failures: Corrects issues like false sensor codes (P0300, P0171, P0174), harsh shifting, and intermittent stalling.
- โ Plug-and-Play: In most cases, no further programming is needed. Just install it and go.
- โ Cost-Effective Repair: Get a fully functional, programmed module for a fraction of the dealer’s price.
Simple Installation Guide: Get Back on the Road Fast
You don’t need to be a master mechanic to replace this part. With basic hand tools, you can do this job in your own driveway.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on electrical components.
- Locate the PCM: On most GM trucks and vans from this era (like the GMC 1500, Tahoe, Suburban, and Express), the PCM is a silver box with multiple large connectors, mounted in the engine compartment on the driver’s side fender wall or near the battery.
- Disconnect the Harnesses: Carefully unclip and pull back the large wiring harness connectors. They have locking tabs, so be gentle.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket.
- Install Your New PCM: Mount the replacement module securely in the bracket and firmly reconnect the wiring harnesses until they click into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Final Step: Turn the key to the ‘ON’ position (without starting) for 30 seconds to allow the system to initialize before starting the engine. Your vehicle is ready to drive!
Expert Pro Tip: Check Your Grounds First!
Before you install your new PCM, take 5 minutes to inspect and clean the main ground connections. The most important one is the braided strap from the back of the engine block to the firewall. On these older GM trucks, a corroded or loose ground can cause voltage drops that create all sorts of bizarre electrical gremlins, perfectly mimicking a failed computer. A wire brush and a wrench can save you a lot of headaches.
Guaranteed Compatibility
This module is a direct replacement for units with service number 9355699 and is interchangeable with the following part numbers: 16266645, 16250279, 16258815, and 09366810. It is confirmed to fit a wide range of GM vehicles, including:
- Chevrolet & GMC C/K 1500, 2500, 3500 Pickups (1998-1999)
- Chevrolet Tahoe & GMC Yukon (1998-1999)
- Chevrolet & GMC Suburban (1998-1999)
- Cadillac Escalade (1999)
- Chevrolet Express & GMC Savana Vans (1998-1999)
- Chevrolet Astro & GMC Safari Vans (1998)
- Oldsmobile Bravada, Chevrolet S10 Blazer, GMC S15 Jimmy (1998)
- And more… please verify your part number to ensure an exact match.
After purchase, please send us your vehicle’s 17-digit VIN so we can program the module before shipping. This step is required to ensure proper function.