Restore Your GM Truck or Van’s Brainpower
Is your trusty 1998-1999 GM truck or van suddenly giving you headaches? Maybe it’s a no-start condition that comes and goes, a check engine light that won’t quit, or shifting that feels rough and unpredictable. Before you start throwing expensive parts at it, the problem might be its electronic brain: the Powertrain Control Module (PCM). This isn’t just another part; it’s the central command center for your engine and transmission. When it fails, it can cause a host of confusing and frustrating issues. We offer a reliable, cost-effective solution: a tested, used OEM PCM, part number 09355699, that arrives at your door pre-programmed for your specific vehicle.
A Technician’s Notebook: The Phantom No-Start
I remember a ’99 Tahoe that was towed into my bay. The owner was at his wit’s end. It would run perfectly for weeks, then refuse to start for no reason. Another shop had already replaced the fuel pump and crank sensor. After hooking up my scanner, I noticed communication with the PCM was intermittent. During one of the no-start events, the PCM went completely offline. A visual inspection showed no damage to the wiring. We swapped in a known-good PCM, and the truck fired up every single time. The original module had an internal hairline fracture on the circuit board that would separate when it cooled down, cutting power. This pre-programmed 1998-1999 Express 1500 PCM is the exact fix for these kinds of hard-to-diagnose electronic gremlins.
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, a faulty module is a likely culprit. Many of these issues can trigger a Check Engine Light, so scanning for codes is a great first step.
- ✔ Unexplained stalling or rough idling
- ✔ Complete no-start condition where the engine cranks but won’t fire
- ✔ Poor fuel mileage
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to pass an emissions test
- ✔ Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error)
- ✔ Loss of communication with the scan tool
The ‘No-Dealer-Needed’ Advantage
The biggest hurdle in replacing a PCM has always been the programming. In the past, you’d have to buy the part, install it, and then have your vehicle towed to a dealership for expensive flashing. We eliminate that entire step. Simply provide us with your vehicle’s 17-digit VIN when you order, and our technicians will flash this module with the latest official GM software for your exact vehicle. It arrives ready for installation, turning a complex job into a manageable one for a DIYer or a quick one for a professional mechanic. This is the most efficient way to get your vehicle back to factory-spec operation.
A Straightforward Guide to Installation
Installing your replacement 1998-1999 Express 1500 PCM is a direct swap. While locations vary slightly across the wide range of compatible vehicles, the process is generally the same.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the PCM: On most of these trucks and vans (like the Express, Savana, Tahoe, and pickups), the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Old Module: Carefully unplug the large electrical connectors. There are usually retaining clips or levers that need to be released. Take your time to avoid damaging the pins or clips.
- Remove the Module: Unbolt the old PCM from its mounting bracket.
- Install the New Module: Bolt your pre-programmed replacement PCM into the bracket and securely reconnect the electrical connectors. You should feel a solid click as they lock into place.
- Reconnect Power: Re-attach the negative battery terminal.
- Security Relearn (If Needed): On some models, you may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the new PCM to sync with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This module, identified by service number 09355699, is a direct replacement for a wide array of GM vehicles. It is also interchangeable with part numbers 16266645, 16250279, 16258815, and 09366810. Please match your part number or verify your vehicle is on the list below to ensure proper fitment.
This part fits many 1998-1999 models including:
- ✔ Chevrolet Express & GMC Savana Vans (1500, 2500, 3500)
- ✔ Chevrolet & GMC Pickups (1500, 2500, 3500)
- ✔ Chevrolet Suburban & Tahoe
- ✔ GMC Yukon & Yukon XL
- ✔ Cadillac Escalade
- ✔ Chevrolet Astro & GMC Safari Vans
- ✔ Chevrolet S10, GMC Sonoma, Isuzu Hombre
- ✔ Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada, GMC Envoy
Note: This is a partial list. The key is matching the part ID 09355699. If you are unsure, please contact us with your VIN.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations your specific vehicle requires from the factory. This includes engine size, transmission type, and any other options, ensuring perfect compatibility and performance.
Is a used part reliable?
Absolutely. We source genuine OEM modules from salvaged vehicles and put them through a rigorous testing process to ensure full functionality. This gives you an OEM-quality part, complete with the latest software updates, at a fraction of the cost of a new one.
What is the security relearn procedure?
It’s a simple process that syncs the new PCM with your vehicle’s Passlock or Passkey anti-theft system. For most GM vehicles of this era, you turn the key to ON (don’t start) for 10 minutes, OFF for 10 seconds, and repeat this cycle 3 times. The vehicle should then start normally.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls transmission line pressure and shift points. If the module is faulty, it can cause harsh shifting, delayed engagement, or failure to shift. Replacing a bad PCM often resolves these issues.
Can I just get one from a junkyard?
You could, but it would not be programmed for your VIN. It would likely prevent the vehicle from starting due to the anti-theft system and would have the wrong calibrations for your specific setup, leading to poor performance. Our service saves you that time, hassle, and the cost of dealer programming.