Restore Peak Performance to Your Chevrolet Astro Van
Is your trusty 1998 or 1999 Chevy Astro van giving you headaches? As the brain of your vehicle’s engine and transmission, a failing Powertrain Control Module (PCM) can cause a host of frustrating and hard-to-diagnose issues. From a van that won’t start to erratic shifting and poor fuel mileage, a faulty PCM can leave you stranded. I’ve spent two decades under the hoods of these vehicles, and I know that replacing the PCM is often the definitive solution to bring these workhorses back to life.
This isn’t just a replacement part; it’s a complete, plug-and-play solution. We take the guesswork and dealer hassle out of the equation. Before this module ships, we flash it with the very latest GM-certified software, programmed specifically to your vehicle’s unique VIN. This ensures perfect communication between all onboard systems, restoring the original performance and efficiency your Astro was built for. Stop chasing symptoms and get the core problem fixed right.
Case Study: A Tricky Diagnosis
A customer brought in a ’99 Astro with a complaint that stumped a couple of other shops: it would randomly stall at stoplights, but only after it was fully warmed up. There were no consistent trouble codes, just a history of random misfires. We checked fuel pressure, ignition components, and sensors—all were fine. After connecting a scope, I noticed the injector pulse width would suddenly drop out on multiple cylinders just before the stall. This pointed to an internal PCM failure. The main processor was overheating and failing under load. We installed one of our VIN-programmed PCMs, and the van has been running flawlessly for the owner ever since. These intermittent issues are classic signs of a failing computer.
Is Your Astro Van Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, a faulty module could be the culprit:
- ✔ Check Engine Light is on with codes for internal processor failure (e.g., P0601, P0606).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle stalls intermittently, especially when warm.
- ✔ Communication errors with your scan tool (U-codes).
- ✔ Apparent failure of multiple sensors at once.
A Straightforward Guide to Installation
Installing your 1998-1999 Astro PCM is a job most DIYers can handle in their own driveway. Follow these steps for a smooth replacement.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for any residual power to drain.
- Locate the PCM: On the Chevy Astro and GMC Safari, the PCM is typically located in the engine compartment on the driver’s side, near the battery.
- Disconnect the Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. There are usually multiple color-coded connectors.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the correct slots on the new PCM. The connectors are keyed to prevent mistakes. Reconnect your battery’s negative terminal.
- Final Steps: Start the engine. In some cases, a security relearn or Crankshaft Variation (CASE) relearn procedure may be required. This can often be done without special tools and instructions are widely available online for these models.
Verified Compatibility for Your GM Vehicle
This module is a direct-fit replacement for service number 16250279 and is also compatible with part numbers 09366810 and 09355699. It is guaranteed to fit the following vehicles (please verify the service number on your original part):
BLAZER S10/JIMMY S15 98 (RH front engine compartment), w/o build date opt ZN4; ID 16250279 or 16258815
BRAVADA 98 (6-262, 4.3L), w/o build date opt ZN4; ID 16250279 or 16258815
CHEVROLET 1500 PICKUP 98-99 (Gasoline, LH engine compartment), ID 16250279
CHEVROLET 2500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
CHEVROLET 3500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
ENVOY 98 (RH front engine compartment), w/o build date opt ZN4; ID 16250279 or 16258815
ESCALADE 99 (LH front engine compartment), ID 16250279
EXPRESS 1500/2500/3500 VAN 98 (Gasoline), ID 16250279
GMC 1500 PICKUP 98-99 (Gasoline, LH engine compartment), ID 16250279
GMC 2500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
GMC 3500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
ISUZU HOMBRE 98 (4.3L), w/o extended build date opt ZN4; ID 16250279 or 16258815
S10/S15/SONOMA 98 (6-262, 4.3L), w/o build date opt ZN4; ID 16250279 or 16258815
SAFARI (GMC) 98-99 (LH front by battery), ID 16250279
SAVANA 1500/2500/3500 VAN 98 (Gasoline), ID 16250279
SUBURBAN 1500/2500 98-99 (Gasoline, LH front engine compartment), ID 16250279
TAHOE 98-99 (Gasoline, LH engine compartment), ID 16250279
YUKON 98-99 (LH engine compartment), ID 16250279
Frequently Asked Questions
Frequently Asked Questions
How does the VIN programming work?
After you place your order, you will need to provide us with your vehicle’s 17-digit VIN. Our technicians use this number to access the latest GM software and flash the module specifically for your vehicle’s factory configuration. This ensures it works correctly right out of the box.
Is this a difficult part to install myself?
For most individuals with basic hand tools, this is a straightforward installation. The module is typically easy to access, and the connectors only fit one way. Please see our installation guide above for the basic steps.
Will I need to do anything after installation?
In most cases, it’s a plug-and-play installation. However, some GM vehicles of this era may require a simple security relearn procedure or a CASE relearn to function perfectly. These procedures do not typically require a dealer visit.
Does this part come with a warranty?
Yes, all of our electronic modules come with a warranty that covers any defects in the part itself. We stand behind the quality of our products and programming service.
Is this the correct part for my vehicle?
This module fits a wide range of GM vehicles. The best way to be certain is to match the service number (e.g., 16250279) from your original PCM to the numbers listed in our compatibility section. If you’re unsure, feel free to contact us with your VIN.