Is Your GM Truck or Van Running Rough?
If your 1999 Cadillac Escalade, Chevy Tahoe, GMC Yukon, or another compatible GM vehicle is suffering from mysterious and frustrating issues, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer of your vehicle, the PCM is responsible for managing everything from the engine’s air-fuel mixture and ignition timing to the transmission’s shift points. When it begins to fail, it can cause a cascade of problems that are difficult to diagnose and can leave you stranded.
From the Diagnostic Bay
We had a 1999 Chevy Tahoe come into the shop that was driving the owner crazy. It would randomly stall at stoplights, the transmission would shift hard out of nowhere, and the check engine light would flicker on and off with a dozen different codes that didn’t seem related. The owner had already replaced the spark plugs, wires, and even the fuel pump with no success. After hooking up our advanced scanner, we noticed the live data stream from the PCM was erratic. Voltage readings were jumping all over the place. We swapped in a known-good, programmed PCM, and it was like a different truck. All the issues vanished instantly. This experience highlights how a single faulty computer can mimic a dozen other mechanical problems, making a reliable replacement essential.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) with various, often unrelated, trouble codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Rough or erratic idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire up.
- ✔ Communication errors with diagnostic scan tools.
Your Direct-Fit, Programmed 1999 Escalade PCM Solution
Don’t let a faulty computer keep your reliable GM truck off the road. This is a genuine, used Powertrain Control Module that has been thoroughly tested and is ready for installation. The most critical part of the process is our professional programming service. Before we ship the unit, we flash it with the latest official GM software updates specifically for your vehicle using the VIN you provide. This ensures optimal performance, fuel efficiency, and emissions control, and it makes the installation process as seamless as possible. You are getting a part that is not just a replacement, but one that is precisely matched to your truck’s factory specifications.
This module is a direct replacement for multiple part numbers, including 16250279 and service ID 09355699 / 9355699. It fits a wide range of popular 1998-1999 GM trucks and vans, such as the Chevrolet Silverado, Suburban, Express, GMC Sierra, Savana, and more. Please verify the part number or consult the detailed fitment list to ensure compatibility with your specific model and engine.
Installation is straightforward for an experienced technician or a skilled DIYer. Once installed, some vehicles may require a simple security relearn procedure (often called a Passlock or VATS relearn) or a Crankshaft Variation Relearn (CASE relearn) to synchronize the new computer with your vehicle’s anti-theft and engine systems. These procedures can often be done without special tools, and instructions are widely available online or in service manuals.
Frequently Asked Questions
What exactly is a PCM and what does it do?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It controls all aspects of the engine and transmission to ensure the vehicle runs efficiently, cleanly, and smoothly. It takes data from dozens of sensors and makes real-time adjustments to fuel injection, spark timing, and gear shifts.
Will I need to do any programming after I receive this computer?
No. We handle the main programming for you. We flash the computer with your vehicle’s specific VIN and the latest GM software before it ships. However, you may need to perform a security relearn procedure after installation for the vehicle to start. This procedure syncs the new PCM with your vehicle’s anti-theft system.
Where do I find my vehicle’s VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on the driver’s side of the dashboard, visible through the windshield.
Is this a new part?
This is a high-quality, tested used part sourced from a salvaged vehicle. Each unit is inspected and verified to be in good working condition before being programmed and shipped. This provides a reliable and cost-effective alternative to a brand new, expensive dealership part.
How can I be sure this PCM will fix my vehicle’s problem?
While this PCM will resolve issues caused by a faulty computer, it’s crucial to have your vehicle properly diagnosed. A PCM failure can mimic other problems, such as bad sensors or wiring issues. We recommend a thorough diagnosis by a qualified mechanic to confirm the PCM is the root cause of your vehicle’s symptoms.
What other part numbers is this compatible with?
This unit is a direct replacement for several part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. The key is to match the service ID number, which is 9355699 for this wide range of applications.