Restore Peak Performance to Your GM Vehicle
Is your 1998 Chevy Astro or other GM truck suffering from frustrating issues like a persistent check engine light, erratic shifting, poor fuel economy, or a dreaded no-start condition? You’re not alone. The Powertrain Control Module (PCM) is the electronic brain of your vehicle, and when it starts to fail, it can cause a cascade of problems that are often difficult to diagnose. This genuine, used OEM PCM, part number 16258815, is the reliable and cost-effective solution you’ve been searching for.
Forget expensive dealership visits and the hassle of finding a shop to program a blank module. We take the guesswork out of the repair. Before this unit ships, we flash it with the latest GM-certified software, specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN). This ensures that all parameters—from fuel delivery and ignition timing to transmission shift points—are perfectly matched to your vehicle’s factory specifications. It’s a true plug-and-play fix designed to get you back on the road with confidence.
A Technician’s Notebook
I remember a 1998 Astro van that came into my shop with a complaint of intermittent stalling at stoplights and a random misfire that wouldn’t set a consistent code. The owner had already replaced plugs, wires, and the distributor cap. After hours of chasing my tail with sensor readings, I finally focused on the PCM. On these older GM vehicles, the internal processors and capacitors can degrade over time, leading to exactly these kinds of ghost-in-the-machine problems. Swapping in a correctly programmed 1998 Astro PCM didn’t just fix the stalling; it smoothed out the idle and even improved the transmission’s shift quality. It’s a reminder that sometimes the root cause is the central controller itself.
Is Your Vehicle Showing These Telltale Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is a likely solution:
- ✔ Persistent Check Engine Light (CEL) with codes like P0601, P0602, or P0605.
- ✔ Vehicle refuses to start or has difficulty starting.
- ✔ Rough or unstable idle.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stalling for no apparent reason.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Your PCM Swap
Installing your pre-programmed 1998 Astro PCM is a job most DIYers can handle with basic tools. While specific locations vary slightly by model, the general process is consistent.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow capacitors to discharge.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine bay, often on the driver’s side fender well or near the battery.
- Disconnect Connectors: Carefully unclip the large wiring harness connectors. They have locking tabs that need to be released. Avoid forcing them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new installation.
- Install the New PCM: Mount the replacement module securely and reconnect the wiring harnesses. Ensure they click firmly into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn (If Needed): On many GM vehicles, you will need to perform a simple key-cycle security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Your vehicle’s service manual will have the exact steps.
Verified Compatibility for Your GM Vehicle
This module is a direct replacement for service number 16258815 and interchanges with several other part numbers. Please verify your vehicle is on this list and that your original module has one of the compatible part numbers (09355699, 16266645, 16250279, 16258815, 09366810). This unit is confirmed to fit the following vehicles with service ID 9355699:
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
EXPRESS 1500/2500/3500 VAN 98-99 (Gasoline)
SUBURBAN 1500/2500 98-99 (Gasoline)
TAHOE 98-99 (Gasoline)
ASTRO 98
BLAZER S10 98
S10 PICKUP 98 (4.3L)
GMC 1500 PICKUP 98-99
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
SAVANA 1500/2500/3500 VAN 98-99 (Gasoline)
YUKON 98-99
SAFARI (GMC) 98
JIMMY S15 98
SONOMA 98 (4.3L)
CADILLAC ESCALADE 99
OLDSMOBILE BRAVADA 98
ISUZU HOMBRE 98 (4.3L)
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after I buy it?
Yes. After your purchase, you MUST send us your vehicle’s 17-digit VIN. We cannot program and ship the module without it. You can add it as a note during checkout or send us a message.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This provides OEM reliability at a fraction of the cost of a new unit.
Why does this 1998 Astro PCM need my VIN?
Your VIN allows us to load the exact software and calibrations your vehicle had when it left the factory. This ensures proper engine and transmission function, and compatibility with your vehicle’s options.
Will I need to have this programmed by a dealer?
No! The main benefit of our service is that the module arrives at your door already programmed and ready for installation. This saves you time and money.
What is the security relearn procedure?
It’s a simple process to sync the new PCM with your vehicle’s anti-theft system. It typically involves a sequence of key turns and waiting periods. We can provide general instructions, but it’s best to consult your owner’s manual for the exact steps for your model.