Restore Peak Performance to Your GM Truck or SUV
Is your vehicle suffering from erratic behavior, a persistent check engine light, or a no-start condition? The Powertrain Control Module (PCM), often called the engine’s brain, is responsible for managing the engine, transmission, and other critical systems. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose problems. This genuine, used PCM, part number 9355699, is the definitive solution to get your vehicle running smoothly and reliably again.
This isn’t just a part off a shelf; it’s a complete, ready-to-install solution. Before we ship it, our expert technicians will program the module using your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures that the PCM has the correct software and calibrations for your exact make, model, and engine combination. It’s loaded with the latest updates from General Motors, often addressing factory bugs and improving performance and efficiency over your original unit. This process eliminates the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
We once had a 1999 Chevy Tahoe in the shop that was driving the owner crazy. It had a random, intermittent stalling issue and a check engine light for an O2 sensor heater circuit. The owner had already replaced the O2 sensor twice, checked all the wiring, and was about to give up. On a hunch, we monitored the data stream from the PCM and noticed the voltage to the O2 heater circuit would drop out randomly. The wiring was perfect. The culprit? A failing driver inside the original PCM. We installed one of our VIN-programmed modules, performed the security relearn, and the problem was gone for good. It’s a classic case where the root cause is the computer itself, not the parts it controls.
Symptoms of a Failing Powertrain Control Module
A faulty PCM can manifest in numerous ways. If you’re experiencing any of the following, your engine computer could be the culprit:
- ✔ Check Engine Light: The light may be on constantly or intermittently, often with codes that point to multiple, unrelated sensor failures.
- ✔ No-Start or Hard Starting: The engine cranks but refuses to start, or takes an unusually long time to fire up.
- ✔ Poor Engine Performance: Noticeable loss of power, hesitation during acceleration, or rough idling.
- ✔ Reduced Fuel Economy: A sudden and unexplained drop in your vehicle’s MPG can be a sign the PCM is not managing the fuel mixture correctly.
- ✔ Erratic Transmission Shifting: Harsh shifts, delayed engagement, or getting stuck in a gear can be caused by the PCM failing to communicate properly with the transmission controller.
- ✔ Stalling: The engine may stall unexpectedly while driving or when coming to a stop.
- ✔ Failed Emissions Test: Inability to pass smog or emissions testing is a common indicator of a PCM issue.
Your Solution: A Pre-Programmed 1998 Envoy PCM
Replacing your vehicle’s PCM can seem daunting, but we make the process straightforward. This module is a direct-fit replacement for a wide range of 1998 and 1999 General Motors trucks, vans, and SUVs. By providing us with your VIN at checkout, you ensure that the unit you receive is tailored specifically for your vehicle. This eliminates compatibility guesswork and ensures all systems function as the factory intended. This is a tested, reliable component sourced from a salvaged vehicle, offering an economical and effective repair.
After installation, you may need to perform a security relearn procedure (often called a CASE relearn or anti-theft relearn). This is a simple process that can typically be done without special tools and involves a sequence of key turns. This procedure syncs the new PCM with your vehicle’s anti-theft system, allowing the engine to start and run. Instructions for this procedure are widely available online for your specific model.
Frequently Asked Questions
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot program and ship the module without it.
Is this a new part?
No, this is a genuine, used OEM part that has been carefully removed from a salvaged vehicle. It has been tested to ensure it is fully functional before being programmed for your vehicle.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of your existing PCM, then yes, this part will resolve the issue. However, if the light is on due to a faulty sensor or other mechanical problem, you will still need to address that separate issue.
Do I need to do anything after I install it?
Yes, in most cases, you will need to perform a security relearn procedure. This syncs the replacement PCM to your vehicle’s anti-theft system. This procedure is simple and typically does not require any special tools.
What if my part number is slightly different?
This module is a direct replacement for several part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. As long as your vehicle is listed in the compatibility chart and your original module is one of these numbers, this part will work.