Is Your 1998-1999 GM Truck or Van Running Rough?
If your late-90s GMC Sierra, Chevy Silverado, Tahoe, or Suburban is experiencing frustrating issues like a persistent check engine light, erratic engine behavior, or even a no-start condition, the culprit is often a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can cause a cascade of problems that are difficult to diagnose. This module, part number 9355699, is the direct-fit, VIN-programmed solution to restore your vehicle’s performance and reliability.
From the Diagnostic Bay
We had a 1999 Chevy Tahoe in the shop that was driving the owner crazy. It had a random misfire that would come and go, and he had already replaced the plugs, wires, cap, and rotor twice. The check engine light was on with a P0300 (Random/Multiple Misfire Detected) code. After checking fuel pressure and for vacuum leaks, we hooked up a scope to the ignition control module signals. Everything looked fine until the engine warmed up, at which point the signal from the PCM would become erratic. The driver inside the PCM was failing under heat. We installed a VIN-programmed replacement module just like this one, performed a CASE relearn, and the Tahoe ran perfectly. It’s a classic example of how a failing PCM can mimic other, more common component failures.
Symptoms of a Failing GM PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stumbling, stalling, or running rough.
- ✔ A noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine cranks but refuses to start.
- ✔ Failure to communicate with diagnostic scan tools.
- ✔ Failing a state emissions inspection.
Why Choose Our Programmed 1998-1999 GMC 1500 PCM?
Don’t settle for a generic, unprogrammed module from a salvage yard that won’t work with your vehicle’s specific systems. Our process ensures you get a part that is truly plug-and-play. This is a genuine, used OEM module that has been meticulously tested and is ready for service. We take your vehicle’s unique Vehicle Identification Number (VIN) and flash the module with the latest, most stable software updates directly from GM. This critical step ensures that the PCM communicates flawlessly with your engine, transmission, anti-lock brake system, and security system (PassLock/VATS).
This service eliminates guesswork and the need for expensive dealership programming. By matching the software to your VIN, we ensure all factory-installed options and parameters are correctly configured, restoring the precise performance your truck had when it left the factory. This is the most reliable and cost-effective way to fix complex electronic issues and get your trusted GM truck or van back on the road.
Simple, Hassle-Free Process
- ✔ Place Your Order: Add this module to your cart and complete the checkout process.
- ✔ Provide Your VIN: After your purchase, simply send us your 17-digit VIN. You can usually find this on your driver’s side door jamb sticker or on the dashboard viewable through the windshield.
- ✔ Installation: Disconnect the battery, swap the module, and reconnect the battery. In most cases, you will need a mechanic with a capable scan tool to perform a Crankshaft Variation Relearn (also known as a CASE relearn) to prevent a P1336 trouble code. Some vehicles may also require a security relearn procedure, which can often be done without special tools.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It controls all aspects of engine performance, including fuel injection, ignition timing, and emissions, as well as automatic transmission shift points.
Why is VIN programming so important for this part?
VIN programming loads the specific software and calibrations for your truck’s engine, transmission, and options. Without it, the module will not work correctly, and your vehicle may not start due to the anti-theft system.
Is this a new part?
No, this is a thoroughly tested, genuine used OEM part sourced from a salvaged vehicle. This ensures OEM quality and fitment at a fraction of the cost of a new module.
Do I need to do anything after I install it?
Yes. After installation, you will likely need a mechanic to perform a Crankshaft Position Sensor Relearn (CASE Relearn) with a professional scan tool. This synchronizes the new PCM with your engine’s sensors and is required to prevent certain trouble codes. A security relearn may also be necessary.
My old module has a different part number, will this work?
This module, 9355699, is a direct replacement for several part numbers, including 16266645, 16250279, 16258815, and 09366810. As long as your vehicle is on the compatibility list, our VIN programming will ensure it functions correctly.