Restore Peak Performance to Your GM Truck or Van
Is your 1998-1999 GMC Yukon, Tahoe, or Suburban running rough, stalling unexpectedly, or throwing a persistent Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the electronic brain of your vehicle. A faulty PCM can cause a cascade of frustrating issues, from poor fuel mileage and erratic shifting to a complete no-start condition. Don’t let a bad computer keep your reliable GM truck off the road. This is a dependable, tested, and pre-programmed replacement PCM that gets you back in control.
We take the guesswork and high cost out of the repair. Unlike a generic module from a parts store or a costly trip to the dealer, this unit arrives at your door ready for installation. We use your vehicle’s VIN to flash the module with the latest, most stable GM factory software. This critical step ensures that the PCM is perfectly matched to your engine, transmission, and specific options, making the installation process as simple as possible. This is the smart, effective solution for any DIY mechanic or professional technician looking to fix it right the first time.
Case Study: A Tricky Diagnosis
I remember a ’99 Chevy Suburban that came into my shop with an intermittent no-start condition that was driving the owner crazy. It would start fine for a week, then suddenly refuse to crank. There were no consistent trouble codes, just a general sense of unreliability. We checked the battery, starter, and ignition switch—all were fine. On a hunch, I monitored the PCM’s data stream during a failed start attempt and noticed the 5-volt reference signal was dropping out. After swapping in a known-good, programmed PCM like this one, the problem vanished instantly. The internal circuitry of the original module was failing under certain temperature conditions, a common issue I’ve seen in over 20 years of diagnostics on these GMT400 platform vehicles.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, your engine computer could be the culprit:
- ✔ Check Engine Light is on, often with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially when warm.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Failure to communicate with a diagnostic scan tool.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle in under 30 minutes with basic hand tools. Our pre-programming service eliminates the need for expensive dealer tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the PCM: On most trucks and SUVs like the Yukon, Tahoe, and Suburban, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the firewall. In Express and Savana vans, it’s often in the LH rear engine compartment.
- Disconnect the Wiring: Carefully unplug the electrical harness connectors from the old module. There are usually two or three large connectors with locking tabs.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you will need it for the new module.
- Install the New PCM: Mount your pre-programmed PCM onto the bracket and securely fasten it. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Final Step: Reconnect the negative battery terminal. Your vehicle may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Start the engine and enjoy a smoother-running truck!
Verified Vehicle Compatibility
This module is a direct replacement for units with service ID number 9355699 or part number 16250279. It is compatible with a wide range of 1998-1999 General Motors vehicles. Please verify the part number on your original module to ensure a perfect match. This part fits:
- ✔ 1998-1999 Chevrolet & GMC C/K 1500/2500/3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban & GMC Suburban (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500/2500/3500 Vans (Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Chevrolet S10, GMC Sonoma, Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada, Isuzu Hombre (4.3L V6)
Frequently Asked Questions
Why do I need to provide my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations for your truck’s specific engine, transmission, and options. This ensures seamless communication between all vehicle systems and is essential for proper function.
Is this part ready to install out of the box?
Yes! Because we program it to your VIN before shipping, it is ready for installation. In some cases, a simple security or CASE relearn procedure may be needed, which can be done without special tools.
Will this fix my transmission shifting problems?
If the shifting issues are caused by faulty signals from the PCM, then yes, this part is very likely to solve the problem. The PCM controls shift points and line pressure based on sensor inputs, so a healthy module is critical for a smooth-shifting transmission.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM (Engine Control Module) typically just controls engine functions. A PCM (Powertrain Control Module) controls both the engine and the automatic transmission, which is the case for these GM vehicles.
This is a used part. How can I be sure it’s reliable?
Each module is sourced from a salvaged vehicle and thoroughly inspected and tested to ensure it is fully functional. We then flash it with the latest stable software from GM, often making it more reliable than the original software that was in your old unit.