Restore Your Truck’s Brain, Not Your Bank Account
Is your 1998 Chevy S10, GMC Sonoma, or another compatible GM truck giving you headaches? If you’re dealing with a frustrating no-start condition, erratic engine behavior, or a persistent Check Engine Light that points to the computer, you’ve found the solution. This is a reliable, tested OEM Powertrain Control Module (PCM), service number 09355699, that serves as the central command for your engine and transmission. Forget the exorbitant dealership quotes and the hassle of finding a shop to program a blank module. We handle the critical step for you.
When you purchase this module, we will flash it with the latest official GM software calibration specifically for your vehicle using the VIN you provide. This ensures that when it arrives, it’s ready to integrate seamlessly, restoring factory performance and communication between all your vehicle’s systems. This isn’t just a part; it’s a complete, cost-effective repair solution for the heart of your truck’s electronics.
Case Study: A Tricky Diagnosis
I remember a ’98 GMC Jimmy with the 4.3L V6 that came into my shop. The owner had spent hundreds chasing an intermittent stalling problem. It would run fine for days, then die at a stoplight without warning and refuse to restart for an hour. There were no consistent trouble codes, just a random U1000 (Loss of Communication) code now and then. After verifying the fuel pressure, ignition system, and all major grounds, we hooked up a scope to the PCM’s power and data lines. We discovered the 5-volt reference signal would momentarily drop out, causing the shutdown. This internal fault is a classic sign of a failing 1998 S10 Sonoma PCM that a basic code scanner will often miss. A replacement programmed module like this one had the Jimmy running reliably in under an hour.
Is Your Truck Exhibiting These Classic PCM Failure Signs?
A failing PCM can cause a wide range of confusing symptoms. If your vehicle is experiencing any of the following, this module is the likely solution.
- ✔ Check Engine Light is on with codes pointing to internal module failure (e.g., P0601, P0602, P0606).
- ✔ The engine will crank but won’t start, even with good fuel and spark.
- ✔ Unexplained stalling or rough idling that isn’t caused by mechanical issues.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete loss of communication with the scan tool.
- ✔ Poor fuel economy and overall decreased engine performance.
A Straightforward Guide to Your PCM Installation
Installing your pre-programmed PCM is a job most DIYers can handle with basic tools. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for capacitors to discharge before starting.
- Locate the PCM: On most of these trucks and vans (like the S10/Sonoma/Blazer), the PCM is located in the engine bay, often near the battery or on the fender wall. It’s a silver metal box with multiple large wiring harness connectors.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the PCM from its mounting bracket.
- Install the New Module: Bolt the replacement PCM into the same location. Reconnect the wiring harnesses firmly, making sure they click and lock into place. A secure connection is critical.
- Reconnect Power: Reattach the negative battery terminal and tighten it securely.
- Perform Security Relearn: Your vehicle is equipped with a Passlock/VATS anti-theft system that needs to sync with the new PCM. The standard procedure is to turn the key to the ‘ON’ position (don’t start) for 10-12 minutes, or until the ‘Security’ light on the dash stops flashing and turns off. Turn the key off for 10 seconds, then repeat this cycle two more times for a total of three cycles. The vehicle should then start.
Verified Compatibility for Your GM Truck or Van
This module, identified by service number 09355699, is a direct replacement for several other part numbers, including 16266645, 16250279, 16258815, and 09366810. It is guaranteed to fit a wide array of 1998 and 1999 GM vehicles. Please confirm your vehicle is on the list below and that your original part has one of these service numbers. Providing your VIN for programming is the final step to ensure perfect compatibility.
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
GMC 1500 PICKUP 98-99 (Gasoline)
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
ASTRO 98
BLAZER S10 98 (w/o build date opt ZN4)
BRAVADA 98 (w/o build date opt ZN4)
ESCALADE 99
ENVOY 98 (w/o build date opt ZN4)
EXPRESS 1500 VAN 98-99
EXPRESS 2500 VAN 98-99 (Gasoline)
EXPRESS 3500 VAN 98-99 (Gasoline)
ISUZU HOMBRE 98 (4.3L, w/o extended build date opt ZN4)
JIMMY S15 98 (w/o build date opt ZN4)
S10/S15/SONOMA 98 (4.3L, w/o build date opt ZN4)
SAFARI (GMC) 98
SAVANA 1500 VAN 98-99
SAVANA 2500 VAN 98-99 (Gasoline)
SAVANA 3500 VAN 98-99 (Gasoline)
SUBURBAN 1500 98-99 (Gasoline)
SUBURBAN 2500 98-99 (Gasoline)
TAHOE 98-99 (Gasoline)
YUKON 98-99
Frequently Asked Questions
Frequently Asked Questions
What exactly is VIN programming?
VIN programming, or flashing, is the process of loading your vehicle’s specific software onto the PCM. This software is determined by your 17-digit Vehicle Identification Number (VIN) and controls everything from fuel mixture and spark timing to transmission shift points and anti-theft settings. We do this for you so the part is ready to install.
Is this a used part?
Yes, this is a thoroughly tested and inspected OEM computer sourced from a salvaged vehicle. This allows us to provide a reliable, factory-correct part at a fraction of the cost of a new unit from the dealer.
Will I need to do anything after installation?
Besides the simple mechanical installation, you will need to perform the vehicle’s security relearn procedure, which takes about 30 minutes and requires no special tools. We’ve outlined the steps in the installation guide above. This syncs the new PCM to your vehicle’s anti-theft system.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s VIN. We cannot ship your order until we receive this information, as the programming is essential for the part to function.
Will this fix my truck’s problem for sure?
This module will resolve any issues directly caused by a failing PCM. While the symptoms listed are very common for PCM failure, we always recommend a proper diagnosis by a qualified mechanic to confirm the PCM is the root cause before purchasing.