Restore Peak Performance to Your GM Van or Truck
Is your 1998-1999 GMC Savana 1500, Chevrolet Express, or other compatible GM vehicle suffering from perplexing issues like stalling, erratic shifting, a persistent check engine light, or a complete no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your vehicle’s engine and transmission. A faulty PCM can disrupt everything from fuel delivery and ignition timing to emission controls, leaving you with an unreliable and inefficient vehicle. This replacement engine computer, part number 16258815, is the definitive solution to restore your vehicle’s original performance and reliability.
The Heart of Your Vehicle’s Operation
The PCM is the unsung hero of your vehicle’s powertrain. It constantly analyzes data from dozens of sensors—like the crankshaft position sensor, oxygen sensors, and throttle position sensor—to make instantaneous adjustments. It ensures the optimal air-fuel mixture, precise ignition spark, and smooth transmission shifts. When it fails, the communication network breaks down, leading to a cascade of performance problems. Replacing a faulty module isn’t just about fixing a problem; it’s about restoring the core logic that makes your engine run as it should.
From the Diagnostic Bay
We had a ’99 Chevy Express 2500 in the shop that was a real head-scratcher. The owner complained of random stalling at stoplights, but it would always start right back up. There were no consistent trouble codes, just a generic communication error that would pop up occasionally. We checked fuel pressure, ignition components, and wiring harnesses for hours. Finally, we monitored the data stream from the PCM and noticed the injector pulse width would drop to zero just before it stalled. It was a failing driver inside the original computer. We installed one of these VIN-programmed modules, and the van has been running perfectly ever since. It’s often the component you suspect last that’s causing the biggest headache.
Symptoms of a Failing PCM
If you’re experiencing any of the following issues, a failing PCM could be the culprit. A proper diagnosis is always recommended, but these are strong indicators that your vehicle’s main computer is on its way out:
- ✔ Unexplained Check Engine Light (CEL) illumination
- ✔ Engine stalling or cutting out unexpectedly
- ✔ Difficulty starting the engine or a no-start condition
- ✔ Poor fuel economy
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Noticeable loss of engine power and acceleration
- ✔ Communication errors with diagnostic scan tools
A Seamless, Programmed Solution for Your 1998-1999 Savana PCM
This isn’t just a used part pulled from a vehicle. It’s a complete, ready-to-install solution. The biggest hurdle when replacing a modern vehicle computer is programming. Without it, the vehicle’s anti-theft system will prevent the engine from starting. We eliminate that obstacle. Upon purchase, you provide us with your vehicle’s VIN. Our technicians then flash the module with the latest, most stable GM-certified software specific to your exact vehicle configuration. This ensures full compatibility and optimal performance, right out of the box. You get a fully functional, plug-and-play module without the exorbitant cost and hassle of a dealership visit.
This unit is a direct replacement for multiple part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. It fits a wide array of GM trucks, vans, and SUVs from the 1998-1999 model years, making it a versatile and reliable choice for your repair.
Frequently Asked Questions
Why do you need my Vehicle Identification Number (VIN)?
Your VIN is essential for us to load the correct GM-approved software onto the PCM. It tells us your vehicle’s engine size, transmission type, emissions equipment, and other specific options. This ensures the module works perfectly with your vehicle’s systems upon installation.
Is this a “plug-and-play” part?
Yes. Because we program the module to your VIN before shipping, it is ready for installation. In most cases, you will not need to perform any additional programming. Simply disconnect the battery, swap the modules, and reconnect the battery.
Will this PCM fix my vehicle’s problem?
This PCM will resolve issues directly caused by a faulty engine computer. While the symptoms listed are common for PCM failure, they can also be caused by other failing components. We always recommend a thorough diagnosis by a qualified mechanic to confirm the PCM is the root cause of your problem.
What if my original part number is not 16258815?
This module is a direct replacement for several part numbers, including 09355699, 16266645, 9355699, and more as listed in the description. As long as your vehicle is listed in the compatibility chart, this module will function correctly once programmed to your VIN.
Is any other procedure required after installation?
For some GM vehicles of this era, a security relearn or Crankshaft Position Sensor (CASE) relearn procedure may be necessary. These are simple procedures that can often be done without special tools. Instructions can be readily found online or in a service manual.