Restore Peak Performance to Your GM Truck or Van
Is your 1998-1999 Chevrolet Express, GMC Savana, or other GM truck plagued by frustrating issues like a persistent check engine light, erratic shifting, poor fuel economy, or a dreaded no-start condition? These are common symptoms of a failing Powertrain Control Module (PCM), the electronic brain of your vehicle. A faulty PCM can disrupt communication between critical systems, leading to a cascade of performance problems that can be difficult to diagnose. This replacement PCM, part number 09366810, is the reliable solution to get your vehicle running smoothly again.
From the Diagnostic Bay
I once had a 1999 Suburban in the shop with a laundry list of complaints: intermittent stalling at idle, a transmission that seemed to have a mind of its own, and a check engine light that would come and go. The owner had already replaced the throttle position sensor and the mass air flow sensor with no luck. After hours of chasing wiring diagrams, we finally hooked up a high-end scanner and noticed the PCM was dropping communication intermittently. A new, properly programmed module fixed every single issue. It’s a reminder that sometimes the root cause is the central controller itself, not just the sensors it’s reading.
Is Your Vehicle Showing Signs of a Bad PCM?
- ✔ Persistent Check Engine Light (CEL) with various communication or sensor codes.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A sudden, unexplained drop in fuel mileage.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Failure to pass an emissions or smog test.
- ✔ Other warning lights on the dash illuminating randomly.
The Critical Role of a Programmed 1998-1999 Express 3500 PCM
The PCM is more than just a simple component; it’s the command center for your engine and transmission. It processes data from dozens of sensors to precisely control fuel injection, ignition timing, emissions systems, and transmission shift points. Because of this complexity, you can’t simply swap a used module from another vehicle. Each PCM is programmed with a Vehicle Identification Number (VIN) specific software that accounts for your vehicle’s engine, transmission, and factory options. Our service eliminates this headache. We flash this genuine used GM module with the latest factory software update for your specific VIN, ensuring it functions as a true plug-and-play replacement. This critical step ensures all systems communicate correctly, restoring the performance and reliability you expect.
This module is a direct replacement for multiple part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. It fits a wide range of popular GM trucks and vans from the era, including the Chevrolet Silverado, GMC Sierra, Tahoe, Yukon, Suburban, and more. Please verify the part number from your original module and consult the extensive fitment list to confirm compatibility.
Frequently Asked Questions
Do I need to provide my VIN?
Yes, providing your vehicle’s 17-digit VIN is mandatory. We use it to load the correct, updated GM software onto the module before shipping. This ensures compatibility and proper function with your specific engine, transmission, and options.
Is any additional programming required after installation?
In most cases, this module is ready to install and run the vehicle. However, on these particular GM models, you will need to have a qualified mechanic with a capable scan tool perform a Crankshaft Variation Relearn procedure (also known as CASE Relearn) to prevent a P1336 trouble code. This is a standard procedure when replacing a PCM on these vehicles.
What does ‘used’ mean for this part?
This is a genuine, original equipment (OEM) module that has been carefully sourced from a salvaged vehicle. Each unit is inspected and then professionally programmed to ensure it is ready for service in your vehicle. This provides OEM reliability at a significant cost saving over a new part from a dealer.
Will this fix my vehicle’s problem for sure?
While this PCM will solve issues directly caused by a faulty module, it’s crucial to ensure your vehicle has been properly diagnosed. This part will not fix problems related to bad sensors, faulty wiring, or other mechanical issues. We recommend a thorough diagnosis by a professional technician before ordering.
Where is the PCM located on my vehicle?
On most vehicles in the fitment list, such as the Express/Savana vans and full-size pickups (Silverado, Sierra, Tahoe, Yukon), the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.