Restore Peak Performance to Your 2004 GM Vehicle
Is your 2004 Chevy Astro, GMC Safari, or another GM vehicle on the fritz? If you’re dealing with frustrating issues like a persistent check engine light, erratic engine behavior, or poor fuel economy, the root cause is often a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM manages everything from fuel injection to transmission shifting. When it fails, it can create a cascade of problems that are difficult to diagnose. This replacement PCM, part number 89017739, is the definitive solution to get your vehicle running reliably again.
We take the guesswork and high cost out of the repair. Unlike a generic part from a big-box store, this module comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We install the latest GM factory software updates before it even ships, ensuring optimal performance and compatibility. This means no expensive trips to the dealership for programming—it’s a true plug-and-play solution for the savvy DIYer or professional mechanic.
From the Diagnostic Bay: The Case of the Intermittent Astro Van
I remember a 2004 Astro van that came into my shop with a problem that was driving the owner crazy. It would start and run fine for days, then suddenly refuse to start. No crank, no start, nothing. After a tow, it would fire right up in the service bay. We checked the battery, starter, and ignition switch—all were fine. The issue was intermittent communication loss with the PCM, a classic sign of internal circuit board failure. After swapping in a VIN-programmed 2004 Astro PCM like this one, the problem vanished for good. These modules can develop heat-related stress fractures on the board, leading to these ghost-in-the-machine type failures that are impossible to predict.
Is Your Vehicle Showing These Symptoms?
- ✔ Persistent Check Engine Light (CEL) with codes like P0601, P0602, or P0606
- ✔ Unexplained drops in fuel mileage (MPG)
- ✔ Engine stalling, stumbling, or hesitating during acceleration
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Vehicle randomly entering ‘limp mode’ with reduced power
- ✔ Complete no-start condition, even with a good battery and starter
- ✔ Communication errors with diagnostic scan tools
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
- ✔ Locate the PCM: On a 2004 Chevy Astro or GMC Safari, the PCM is located in the engine compartment on the driver’s side, near the battery. For other models, its location may vary (check the fitment list below).
- ✔ Disconnect the Old Module: Carefully unplug the electrical wiring harnesses from the old PCM. These connectors have locking tabs that need to be released before they can be pulled out.
- ✔ Swap the Modules: Unbolt the old PCM from its mounting bracket and set it aside. Mount the new module securely in its place.
- ✔ Reconnect and Finalize: Plug the wiring harnesses firmly into the new PCM until they click into place. Reconnect the negative battery terminal.
- ✔ Post-Installation Procedure: While not always required, some vehicles may need a Crankshaft Position System Variation (CASE) relearn procedure performed with a capable scan tool to ensure perfect timing and prevent a CEL.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 89017739 and 12586243. It is guaranteed to fit the following 2004 models (please verify the location notes):
- ✔ ASTRO / SAFARI (GMC): (LH front by battery)
- ✔ AVALANCHE 2500: (LH front under battery)
- ✔ BLAZER S10/JIMMY S15: (RH front engine compartment)
- ✔ CORVETTE: (RH engine compartment, ID 12586243)
- ✔ CTS (2004-2005): (V-Series, RH engine compartment, ID 12586243)
- ✔ ENVOY XL / XUV & TRAILBLAZER EXT (5.3L): (Next to air box, check ID)
- ✔ EXPRESS / SAVANA VAN (1500, 2500, 3500): (LH rear engine compartment)
- ✔ GTO: (Main, LH engine)
- ✔ RAINIER (5.3L): (Next to air box, check ID)
- ✔ S10/S15/SONOMA: (RH front engine compartment)
- ✔ SIERRA / SILVERADO 1500 (4.3L): (LH front under battery, w/o hybrid)
- ✔ SIERRA / SILVERADO 2500 / 3500 (8.1L Gasoline): (LH front under battery)
- ✔ SSR: (Next to air box, check ID)
- ✔ SUBURBAN 2500 (8.1L): (LH front under battery)
- ✔ YUKON XL 2500 (8.1L): (LH front under battery)
Frequently Asked Questions
Do I need to get this PCM programmed by a dealer?
No. We handle the programming for you before we ship the item. Simply provide your vehicle’s VIN at checkout, and it will arrive ready to install with the latest GM software.
What is a VIN and why do you need it?
The VIN is your vehicle’s unique 17-digit serial number. We use it to load the exact factory software and calibrations for your specific engine, transmission, and options, ensuring a perfect match.
Where is the PCM on my 2004 Astro van?
On the 2004 Chevrolet Astro and GMC Safari, the PCM is located in the engine bay on the driver’s side (LH), right by the battery.
Will this fix my transmission shifting problems?
Since the Powertrain Control Module (PCM) controls both the engine and transmission, a faulty module is a very common cause of harsh or erratic shifting. If the module is the cause, this part will resolve the issue.
Is this part difficult to install for a DIYer?
Not at all. For most models, it’s a simple unbolt-and-unplug process that requires basic hand tools. Our pre-programming service eliminates the most difficult step, making this a very DIY-friendly repair.