Get Your GM Truck or Van Running Right Again
Is your 1998 GMC Safari or another compatible GM vehicle giving you headaches? If you’re dealing with frustrating issues like stalling, no-start conditions, a persistent check engine light, or erratic transmission shifting, a failing Powertrain Control Module (PCM) is often the culprit. As the brain of your vehicle, when the PCM starts to fail, it can cause a cascade of problems that are difficult to diagnose. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded. Stop throwing parts at the problem and get the direct-fit, correctly programmed solution.
This is a genuine OEM engine computer, service ID 9355699, that has been carefully sourced from a salvaged vehicle and is ready for a new life in your truck or van. The real value here is our professional programming service. Before we ship it, we flash the module with the latest GM-authorized software updates, specifically matched to your vehicle’s VIN. This critical step ensures seamless communication with your vehicle’s other modules and often corrects drivability quirks that may have existed from the factory. You get a reliable part that’s ready to install right out of the box, saving you a costly trip to the dealership for programming.
A Technician’s Notebook: The Phantom No-Start
I once had a 1998 Chevy Express van in my bay that would randomly refuse to start. The owner had replaced the battery, starter, and fuel pump, but the problem persisted. There were no consistent trouble codes, just an intermittent no-crank, no-start. After checking all the basics, I hooked up my high-end scanner and monitored the PCM data stream. I noticed that during the no-start events, the PCM wasn’t sending the ‘crank’ signal to the starter relay. It was an internal failure within the computer itself, a classic sign of aging electronics on these workhorse vans. We swapped in a VIN-programmed PCM just like this one, and the van fired up every single time. It’s a fix I’ve performed hundreds of times on these GM platforms.
Is Your GM Truck or Van Showing These Signs?
- ✔ Unexplained Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes for internal module failure (e.g., P0601, P0606)
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Engine stalling, stumbling, or running rough
- ✔ Intermittent no-start or difficulty starting
- ✔ Poor fuel economy
- ✔ Failure to communicate with a diagnostic scan tool
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- ✔ Locate the PCM: On most compatible vehicles like the GMC Safari and Chevy Astro, the PCM is located in the engine compartment, typically near the battery on the driver’s side. On Express/Savana vans, it’s often on the left-hand rear side of the engine compartment.
- ✔ Disconnect the Old Module: Carefully unplug the electrical connectors. These GM connectors from the 90s have locking tabs that may require a small flathead screwdriver to gently release. Never pull by the wires.
- ✔ Remove the Module: Unbolt the old PCM from its mounting bracket. There are usually two or three bolts holding it in place.
- ✔ Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely plug in the electrical connectors. You should hear a ‘click’ as they lock into place.
- ✔ Reconnect the Battery: Re-attach the negative battery terminal.
- ✔ Perform Security Relearn (If Needed): On many of these GM vehicles, you will need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. This allows the new PCM to sync with your vehicle’s anti-theft system.
Will This Fit My Vehicle?
This PCM is a direct replacement for units with service ID number 9355699. It fits a wide range of popular GM trucks, vans, and SUVs from the late 1990s. While we’ve listed many below, the most important step is to provide your VIN upon purchase so we can guarantee perfect software compatibility. This part is verified to fit the following models (and more):
- ✔ 1998 GMC Safari & Chevrolet Astro
- ✔ 1998-1999 GMC/Chevy C/K 1500, 2500, 3500 Pickups (Gasoline)
- ✔ 1998-1999 GMC/Chevy Suburban (Gasoline)
- ✔ 1998-1999 GMC Yukon & Chevrolet Tahoe
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 GMC Savana & Chevrolet Express Vans (Gasoline)
- ✔ 1998 S10, S15, Sonoma, Blazer, Jimmy, Bravada, Envoy, Hombre (4.3L V6)
Frequently Asked Questions
Do I need to do anything after I install it?
Because this PCM comes pre-programmed to your VIN, it is nearly a plug-and-play installation. However, you will likely need to perform a simple ‘Security Relearn Procedure’ which takes about 30 minutes and requires only your ignition key. We include instructions for this common procedure.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to load the exact, correct GM software for your vehicle’s specific engine, transmission, and options. This ensures perfect compatibility and performance, just as if it came from the factory.
Is this a new part?
No, this is a high-quality, tested OEM part sourced from a salvaged vehicle. We find that genuine OEM electronics often have superior longevity compared to some aftermarket alternatives. Each unit is inspected and programmed with the latest software before shipping.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM (e.g., code P0601), then yes, this will resolve the issue. However, you should always ensure other potential causes have been ruled out. This module will not fix problems related to other failed sensors or mechanical parts.
What if my part number is slightly different?
This module, with service ID 9355699, directly replaces several other part numbers including 16266645, 16250279, and 16258815. As long as your vehicle is on the compatibility list, our VIN programming will ensure it works correctly.