Restore Peak Performance to Your GM Truck or Van
Is your 1998-1999 Chevy Express or GMC Savana suffering from frustrating issues like stalling, rough idling, poor fuel economy, or an illuminated Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your vehicle’s engine and transmission. A faulty PCM can make your reliable workhorse feel unpredictable and unsafe. This genuine, used GM PCM is the definitive solution to get your vehicle running smoothly and efficiently again.
This isn’t just a replacement part; it’s a fully programmed, plug-and-play solution. Before we ship it, our technicians will flash the module with the latest GM-certified software updates, specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN). This critical step ensures seamless communication between the new PCM and all your vehicle’s systems, eliminating the need for an expensive trip to the dealership for programming. Simply provide your VIN after purchase, and we’ll handle the rest.
From the Diagnostic Bay
We once had a 1999 Suburban come in with classic ‘bad PCM’ symptoms: intermittent stalling, erratic gauge behavior, and a no-communication code with our scan tool. The owner had already replaced the fuel pump and ignition coil with no luck. Before condemning the expensive computer, we did a voltage drop test on the main PCM ground wires. Sure enough, we found a corroded ground connection on the engine block. After cleaning the connection point, all the symptoms vanished. It’s a powerful reminder: always check your grounds! A 10-minute check can save you from replacing a perfectly good module.
Diagnosing Your 1998-1999 Express 2500 PCM
The PCM is the brain of your vehicle’s operation, and when it starts to fail, the symptoms can be widespread and confusing. If you’re experiencing any of the issues below, a failing computer is a likely culprit. This module is a direct replacement for several part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810, ensuring broad compatibility across the GM truck and van lineup from this era.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light: The light is on, and you may have codes related to sensor circuits, module communication, or processor faults.
- ✔ Engine Stalling: The engine may stall intermittently for no apparent reason, either while driving or at idle.
- ✔ No-Start Condition: The engine cranks but refuses to start, often due to a lack of fuel injector pulse or spark command from the PCM.
- ✔ Poor Fuel Economy: A sudden and unexplained drop in MPG can be caused by the PCM failing to properly manage the air-fuel mixture.
- ✔ Rough or Erratic Idle: The engine idles poorly, surges, or hunts for a stable RPM.
- ✔ Harsh or Failed Shifting: The transmission may shift erratically, slam into gear, or fail to shift at all, as the PCM also controls transmission functions.
- ✔ Failed Emissions Test: Inability to pass smog or emissions testing is a common indicator of a malfunctioning engine computer.
Replacing your faulty module with our VIN-programmed unit is the most effective way to resolve these issues and restore your vehicle’s original performance and reliability. Installation is straightforward for a DIY mechanic; the module is typically located in the engine compartment and can be swapped with basic hand tools. Once installed, a simple security relearn procedure may be required, which can be done without any special tools.
Frequently Asked Questions
Why do I need to provide my VIN?
Your vehicle’s VIN (Vehicle Identification Number) is essential. It allows us to load the exact, correct GM software for your truck’s specific engine, transmission, and options. This ensures the PCM works perfectly right out of the box, saving you a trip to the dealer for expensive programming.
Is this part difficult to install?
No, installation is generally straightforward. The PCM is usually located in the engine bay (on the driver’s side). It involves disconnecting the battery, unplugging the electrical connectors, and unbolting the old module. The new one bolts in the same way. In most cases, a simple security relearn procedure is all that’s needed afterward.
Will this computer be plug-and-play?
Yes, because we program it to your VIN, it is designed to be a plug-and-play solution. After installation, you may need to perform a security relearn (often called a ‘key relearn’ or ‘anti-theft relearn’), which typically involves cycling the ignition key and can be done in your driveway without special tools.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM means Powertrain Control Module. A PCM is a type of ECM that controls both the engine and the transmission. For your 1998-1999 GM vehicle, this module functions as the PCM.
This is a used part. How can I be sure it works?
Every module we sell is sourced from a salvaged vehicle and thoroughly inspected and tested to ensure it is fully functional. We then flash it with fresh, updated software. This process ensures you receive a reliable, working computer ready for installation.