Is your Chevrolet Astro, Express van, or GMC truck suffering from perplexing issues like a persistent check engine light, erratic shifting, or a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your vehicle’s engine and transmission performance. Don’t let a faulty module keep your reliable GM vehicle off the road. This direct-fit PCM, part number 16265035, is the definitive solution to restore its performance, efficiency, and dependability.
This isn’t just a replacement part; it’s a fully integrated solution. Before we ship it, we program the module with the latest GM factory software updates, specifically matched to your vehicle using the VIN you provide. This critical step ensures seamless communication between the PCM and all other vehicle systems, eliminating the need for an expensive trip to the dealership for programming. It’s designed to get you back on the road quickly and confidently.
We had a 2000 Chevy Express 2500 work van come in that was a real head-scratcher. The owner had replaced the throttle position sensor twice, cleaned the MAF sensor, and even put in new spark plugs, but it still had a lazy throttle response and would occasionally stall at idle. The codes were intermittent and pointed towards a lean condition. After chasing our tails checking for vacuum leaks, we finally hooked up a scope to the sensor reference voltage line from the PCM. We saw the 5-volt reference signal fluctuating wildly. The PCM’s internal voltage regulator was failing, sending bad data to all the sensors. A new, correctly programmed PCM fixed everything instantly. It’s a reminder that when multiple, seemingly unrelated sensor codes appear, the source of the problem is often the computer itself.
Common Symptoms of a Failing GM PCM
If you’re experiencing any of the following issues, a failing PCM could be the culprit. A faulty module can cause a cascade of problems that are often misdiagnosed as individual sensor or component failures.
- ✔ Persistent Check Engine Light (CEL) with various trouble codes
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Complete no-start or intermittent starting condition
- ✔ Poor fuel economy and loss of power
- ✔ Failure to pass emissions testing
- ✔ Communication errors with diagnostic scan tools
Why Choose Our Pre-Programmed 1999-2001 Astro PCM?
This module is the ideal choice for a wide range of GM trucks and vans from the late 90s and early 2000s. We handle the complex part of the repair for you. By programming the unit to your vehicle’s specific VIN, we ensure that it has the correct software for your engine, transmission, and emissions equipment. This VIN-matching process is essential for proper vehicle operation and is a service that sets our modules apart.
Installation is straightforward for a DIY mechanic or any professional technician. Once installed, you may need to perform a security relearn or Crankshaft Variation (CASE) relearn procedure, which can often be done without special tools. This ensures your vehicle recognizes the new module and operates smoothly. This unit is a direct replacement for multiple part numbers, including: 16263494, 16265035, 8162634940, 218-11787, and 21811787.
Get your truck or van running like new again. Restore the crisp engine response and smooth shifting you depend on with this reliable, pre-programmed powertrain control module.
Frequently Asked Questions
Do I need to get this PCM programmed by a dealer?
No. We program the module to the VIN you provide before shipping. This ensures it’s loaded with the correct GM software for your specific vehicle, saving you time and money.
Is this a plug-and-play part?
Mostly, yes. Because it comes programmed, it will control the engine and transmission upon installation. However, on many GM vehicles, you will need to perform a security relearn procedure (also called Passlock/Passkey) for the vehicle to start. A Crankshaft Variation (CASE) relearn may also be needed to clear certain engine codes.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information.
Where is the PCM located on my vehicle?
The location varies by model. On a Chevy Astro or GMC Safari, it’s typically on the driver’s side in the engine bay, near the battery. On Express and Savana vans, it’s often in the rear driver’s side of the engine compartment. On S10/Blazer models, it’s usually on the passenger side firewall. Always disconnect the battery before removal or installation.
Will this fix my transmission shifting problems?
If the shifting problems are caused by faulty electronic commands from the PCM, then yes, this module will resolve them. The PCM controls transmission line pressure and shift points. However, it will not fix internal mechanical failures within the transmission itself.