Is Your GM Truck or Van Acting Up?
If your 1998 Chevrolet Astro, or another compatible GM vehicle, is suffering from frustrating issues like intermittent stalling, a persistent check engine light, rough idling, or a complete no-start condition, the root cause might be a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM is responsible for managing everything from fuel injection and ignition timing to transmission shifting. When it fails, it can create a cascade of problems that are often difficult to diagnose.
From the Diagnostic Bay
We had a 1998 GMC Safari (a sibling to the Astro) come into the shop with an intermittent stalling problem that was driving the owner crazy. It would die at stoplights without warning, but then start right back up. We checked the fuel pressure, ignition system, and scanned for codes, but everything seemed to be in spec. On a hunch, we monitored the PCM’s live data stream during a long test drive. We noticed the injector pulse width signals were dropping out randomly just before the engine would quit. After swapping in a known-good, programmed PCM, the problem vanished. It’s a classic example of how a failing computer can mimic a mechanical issue, making proper diagnosis key.
The Direct-Fit Solution for Your Vehicle
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We are offering a genuine, used OEM PCM that has been thoroughly tested for full functionality. The most critical part of the process is our professional programming service. Before we ship the module, we use your vehicle’s unique Vehicle Identification Number (VIN) to flash it with the latest official GM software updates. This ensures that the computer is perfectly matched to your engine, transmission, and factory options, eliminating compatibility guesswork and simplifying the installation process.
Why Our Programmed 1998 Astro PCM is the Right Choice
Replacing a PCM can be intimidating, but our service makes it straightforward. A new module from a dealership can be prohibitively expensive, and a generic one from a local parts store won’t come programmed, requiring an additional, costly trip to a mechanic with specialized tools. This tested, used OEM unit provides the reliability of a factory part, paired with the convenience of pre-shipping programming, all at a cost-effective price. This specific 1998 Astro PCM is the brain your vehicle needs to run smoothly and efficiently again.
Common Symptoms of a Failing GM PCM
- ✔ Check Engine Light is on with various communication or sensor codes.
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained stalling or stumbling, especially when warm.
- ✔ Rough or erratic engine idle.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Failure to pass an emissions test.
This module, service number 16250279, is a direct replacement for several part numbers including 09355699, 16266645, 9355699, 16258815, 09366810, and 9366810. It fits a wide range of Chevrolet and GMC trucks, vans, and SUVs from the late 1990s. Please verify your part number and consult the detailed fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to get this computer programmed?
No. The main benefit of our service is that we program the module for you before it ships. Simply provide us with your vehicle’s VIN during or after checkout, and we will handle the rest.
What is a VIN and why do you need it?
The VIN is your 17-digit Vehicle Identification Number, found on your dashboard, driver’s side door jamb, and registration. It allows us to access the specific GM software calibration file for your vehicle’s engine, transmission, and factory-installed options, ensuring a perfect match.
Is this a new part?
This is a high-quality, tested, and guaranteed functional used OEM part sourced from a salvaged vehicle. This ensures OEM-level reliability and fitment without the high cost of a new-from-dealer part.
Will this fix my vehicle’s problem for sure?
This module will resolve any issue directly caused by a faulty PCM. However, it’s crucial that your vehicle has been properly diagnosed. This part will not fix problems related to bad sensors, wiring, or mechanical failures. We recommend confirming the diagnosis before ordering.
What is a CASE relearn and will I need to do one?
CASE stands for Crankshaft Angle Sensor Error. After installing a new PCM, the engine may set a code (like P1336) because the new computer needs to learn the specific variations of your engine’s crankshaft position sensor. This “relearn” procedure is often required and can be performed by most shops with a capable scan tool. Your vehicle will typically run and drive without it, but the check engine light may be on until the procedure is completed.
Where is the PCM located on a 1998 Chevy Astro?
On the 1998 Astro and Safari vans, the PCM is typically located in the engine compartment on the driver’s side, near the battery and coolant overflow tank. It is a silver metal box with several large electrical connectors.