Is Your 1998-1999 GM Truck or SUV Running Rough?
If you’re dealing with a frustrating no-start condition, erratic engine performance, poor fuel economy, or a persistent Check Engine Light on your 1998-1999 Chevy Tahoe, GMC Yukon, or other compatible GM vehicle, 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 fuel injection and ignition timing to transmission shifting and emissions controls. When it fails, it can cause a cascade of problems that are difficult to diagnose and can sideline your truck indefinitely.
This replacement Powertrain Control Module, service number 09355699, is the definitive solution to get your vehicle back on the road. We take the guesswork out of the repair by pre-programming the module specifically for your truck or SUV using your Vehicle Identification Number (VIN). This ensures that all factory settings, engine parameters, and security information are a perfect match, just like the original unit from the factory.
From the Diagnostic Bay
We had a ’99 Suburban come into the shop with a complaint of harsh, unpredictable shifting and a Check Engine Light for a transmission solenoid code. The owner had already spent a small fortune replacing the transmission, but the problem persisted. After hooking up our diagnostic scanner, we noticed intermittent communication drops with the engine controller. A quick check of the PCM’s power and ground circuits confirmed they were solid. The issue was internal to the original computer. We installed a VIN-programmed PCM, performed the security relearn, and the truck shifted perfectly. The customer could have saved thousands by addressing the real problem first—the 1998-1999 Tahoe PCM was the root cause all along.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is illuminated with various, often inconsistent, trouble codes.
- ✔ Engine cranks but refuses to start.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Stalling, stumbling, or hesitation during acceleration.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Misfire codes (P0300-P0308) even after replacing plugs, wires, and coils.
Why Choose Our Pre-Programmed 1998-1999 Tahoe PCM?
Finding a reliable replacement computer for these classic GM trucks can be a challenge. Our process simplifies the repair. This isn’t just a generic, off-the-shelf part. Each module is meticulously programmed with the latest GM-certified software updates for your specific VIN. This process corrects many of the original factory software issues, leading to improved performance, shifting, and overall drivability. By providing us with your VIN at checkout, you receive a module that is ready for installation and the subsequent security relearn procedure, which is a necessary step for these vehicles.
This module is a direct replacement for part numbers 09355699, 16250279, and 09366810, and fits a wide array of GM models including the Chevrolet Tahoe, Suburban, C/K Pickups, Express Van, and their GMC counterparts like the Yukon, Sierra, and Savana. Please verify the part number on your original module or consult the detailed fitment list to ensure compatibility.
Installation and Security Relearn
Physically replacing the PCM is straightforward. It is typically located in the engine bay on the driver’s or passenger’s side. After swapping the hardware, you MUST perform a security relearn procedure (often called Passlock or Passkey relearn). This synchronizes the new PCM with your vehicle’s anti-theft system. Without this step, the vehicle will not start. The procedure is simple and does not require a special scan tool. Instructions are widely available online or can be provided upon request.
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 the engine and transmission functions by reading data from various sensors and making real-time adjustments to fuel delivery, spark timing, and shift points to ensure optimal performance, fuel efficiency, and emissions.
Is this module truly plug-and-play?
It is as close as it gets. We program it with your VIN, so all the engine and transmission software is correct. However, you MUST perform a security relearn procedure after installation to sync the module with your vehicle’s anti-theft system. The engine will not start until this is completed.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). You can typically add it as a note during checkout or send it to us in a message referencing your order number. We cannot ship the module until we have your VIN.
Where is the PCM located on my vehicle?
On most 1998-1999 GM full-size trucks and SUVs like the Tahoe, Yukon, and pickups, the PCM is located in the engine compartment, usually on the driver’s side inner fender. On S-series trucks (S10, Blazer) and Astro/Safari vans, it can be on the passenger side or near the battery.
What happens if I don’t perform the security relearn?
If the security relearn is not performed, the vehicle’s anti-theft system will activate, preventing the engine from starting. The engine may crank but will not fire up, and you will likely see a flashing security light on the dashboard.