Is Your GM Truck or Van Running Rough?
If you’re dealing with frustrating issues like a persistent check engine light, erratic engine performance, poor fuel economy, or harsh transmission shifting, the problem might be the very brain of your vehicle: the Powertrain Control Module (PCM). For a wide range of 1998 and 1999 General Motors vehicles, a failing PCM can turn a reliable workhorse into a source of constant headaches. This module is the central command unit, and when it falters, the entire vehicle suffers. Don’t let a faulty computer keep you off the road. We have the reliable, plug-and-play solution you need.
The Direct-Fit Solution: A Programmed GM PCM 09355699
This isn’t just a replacement part; it’s a complete solution. This is a genuine, used GM PCM, part number 09355699, sourced from a salvaged vehicle and rigorously tested for full functionality. The most critical service we provide is programming. Before this module ships, we flash it with the latest official GM software updates, specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN). This means you receive a module that is ready to install right out of the box, eliminating the need for an expensive trip to the dealership for programming. It’s designed to restore your vehicle’s original performance, efficiency, and reliability.
From the Diagnostic Bay
We had a ’99 Chevy Tahoe come in that was driving the owner crazy. It would randomly stall at stoplights, and the transmission would sometimes refuse to shift out of first gear. He had already replaced the fuel pump and a handful of sensors with no luck. We hooked up our scanner and saw some erratic data from the PCM and a few communication error codes. After confirming the wiring was solid, we suspected the module itself. We sourced a tested unit, flashed it to the Tahoe’s VIN, and installed it. The difference was immediate. The engine idled smoothly, the transmission shifted perfectly, and the stalling issue was completely gone. It’s a classic case of how a failing computer can mimic a dozen other mechanical problems.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various, often inconsistent, trouble codes.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to start, or intermittent no-start conditions.
- ✔ Noticeable decrease in fuel economy.
- ✔ Failure to pass an emissions test.
- ✔ Communication errors with diagnostic scan tools.
Why Choose Our Pre-Programmed PCM?
Getting your vehicle fixed shouldn’t be complicated. Our process is designed to be as simple as possible. You order the part, provide us with your VIN, and we handle the complex programming. This saves you time, money, and the hassle of coordinating with a repair shop or dealership. This module is a direct replacement for multiple part numbers, including 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810, ensuring broad compatibility across dozens of GM models from the era.
Installation Note: Installation is straightforward for those with basic mechanical skills. Always disconnect the negative battery terminal before beginning. Locate your existing PCM (often in the engine bay on the driver’s or passenger’s side fender), carefully disconnect the wiring harnesses, and unbolt the module. Install the new module, reconnect the harnesses, and then reconnect the battery. In many cases, the vehicle will start and run perfectly. However, for optimal performance, a Crankshaft Variation Relearn (also known as a CASE relearn) may be required using a capable scan tool to prevent a P1336 trouble code.
Frequently Asked Questions
Do I need to get this PCM programmed?
No. The main benefit of our service is that we program the module for you before it ships. Simply provide your vehicle’s VIN during or after checkout, and it will arrive ready to install.
Is this a new part?
This is a high-quality, used OEM part that has been carefully removed from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional and reliable.
Where is the PCM located on my truck or van?
On most compatible models like the Astro, Safari, Tahoe, Yukon, and pickups, the PCM is located in the engine compartment, typically on the driver’s side near the battery or on the inner fender. For Express and Savana vans, it’s often in the LH rear of the engine compartment.
What is a CASE relearn and will I need to do one?
A CASE (Crankshaft Angle Sensor Error) relearn procedure synchronizes the PCM with the crankshaft position sensor. While the vehicle will run without it, performing this procedure with a compatible scan tool is recommended to ensure optimal engine timing and prevent a P1336 trouble code. Many local repair shops can perform this service for you.
How do I provide my VIN?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship the part until we have this information to complete the programming.