Is Your 1998-1999 GM Van or Truck Running Poorly?
If you’re dealing with frustrating issues like a persistent check engine light, rough idling, stalling, poor fuel mileage, or even a no-start condition in your Chevrolet Express, GMC Savana, or other compatible GM vehicle, the root cause is often a failing Powertrain Control Module (PCM). As the central computer, the PCM is responsible for managing everything from fuel delivery and spark timing to transmission shifting. When it fails, it can create a cascade of problems that are difficult to diagnose. The solution is a reliable replacement, and the heart of these issues often lies with a faulty 1998-1999 Express 1500 PCM.
From the Diagnostic Bay
We recently had a ’99 Savana 2500 work van towed in that had been to two other shops for an intermittent stalling problem. The owner had already replaced the fuel pump, ignition coil, and crank sensor with no luck. After verifying good power and grounds to the PCM, we hooked up a scope and saw the 5-volt reference signal to the sensors was dropping out randomly. This is a classic internal PCM failure. We installed one of these VIN-programmed units, performed the quick security relearn, and the van fired up and ran perfectly. It’s a textbook example of how a failing computer can mimic other component failures, making accurate diagnosis key.
Common Signs of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine misfires, stumbles, or hesitates during acceleration.
- ✔ Rough or erratic idling.
- ✔ A significant drop in fuel economy.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ The vehicle cranks but will not start.
- ✔ Communication errors with diagnostic scan tools.
Why Choose Our Programmed 1998-1999 Express 1500 PCM?
This isn’t just a used part pulled from a yard. This is a complete, ready-to-install solution. We take a thoroughly tested, functional PCM from a salvaged vehicle and program it specifically for YOUR vehicle using the 17-digit Vehicle Identification Number (VIN) you provide. This process ensures that the module has the correct software and calibrations for your van’s specific engine, transmission, and options. We load the latest available updates from GM, which can often resolve factory bugs and improve performance and longevity. This saves you a costly trip to the dealership for programming and allows for a straightforward installation.
Simple Installation Process
Once you receive your pre-programmed module, the installation is simple:
- Disconnect the Battery: Always disconnect the negative battery terminal before working on vehicle electronics.
- Locate and Replace the PCM: On most of these vans and trucks, the PCM is located in the engine bay, often on the driver’s side fender well. Disconnect the electrical connectors and unbolt the old unit.
- Install the New PCM: Bolt the replacement module in place and securely reconnect the electrical harnesses.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn: Your vehicle is equipped with a Passlock security system that will need to be synchronized with the new PCM. This is a simple procedure that you can do yourself (instructions are widely available online and typically involve turning the key to the ‘ON’ position for 10-15 minutes).
By providing a module that is already flashed for your vehicle, we eliminate the most complex step of the repair. Get your van back in service with a reliable, correctly programmed 1998-1999 Express 1500 PCM and restore its original performance and dependability.
Frequently Asked Questions
Do I need to have this computer programmed?
No. We handle the programming for you before we ship the part. Simply provide us with your vehicle’s 17-digit VIN during or after checkout, and it will arrive ready for installation.
Is this a new part?
This is a high-quality, used OEM part that has been sourced from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional before being programmed and shipped.
What is the security relearn procedure?
This is a simple process to sync the new PCM with your vehicle’s anti-theft system. It typically involves turning the key to the ‘ON’ position for about 10 minutes, then off, and then starting the vehicle. Specific instructions for your GM vehicle are easy to find online.
How do I find my VIN?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on a plate on the driver’s side of the dashboard visible through the windshield.
Will this PCM fit other vehicles besides the Express 1500?
Yes, this module fits a wide range of 1998-1999 GM trucks and vans, including the GMC Savana, Chevrolet/GMC Pickups, Tahoe, Yukon, Suburban, and more. Please check the detailed fitment list on this page to confirm compatibility with your specific model.