Is Your Late 90s GM Truck or Van Running Rough?
If you’re dealing with frustrating issues like a persistent Check Engine Light, poor fuel economy, erratic shifting, or even a no-start condition in your 1998-1999 GM vehicle, the problem may lie with its electronic brain: the Powertrain Control Module (PCM). As the central command center for your engine and transmission, a failing PCM can cause a cascade of problems that are often misdiagnosed, leading to expensive and unnecessary repairs. This genuine OEM PCM, part number 09355699, is the reliable and cost-effective solution to restore your vehicle’s performance and dependability.
From the Diagnostic Bay
We had a 1999 GMC Yukon come into the shop with a complaint of a harsh 1-2 shift and a random engine stall at idle. The owner had already replaced the throttle position sensor and the idle air control valve, but the problems persisted. After hooking up our diagnostic scanner, we noticed erratic data coming from several sensors, but the sensors themselves tested fine. This pointed us directly to the PCM. The internal processors were failing, corrupting the signals. We installed a correctly programmed PCM, performed the security relearn, and the Yukon ran like new. It’s a classic case where chasing individual symptoms can be costly; sometimes, you have to go straight to the source.
The Direct-Fit Solution for Your 1998-1999 Chevrolet PCM
Don’t settle for a generic, one-size-fits-all module. This PCM is specifically programmed to your vehicle’s unique Vehicle Identification Number (VIN). This critical step ensures that all factory settings for your engine, transmission, and emissions equipment are perfectly matched. We load the latest GM-certified software updates, which can resolve common drivability issues and improve overall performance. This is a genuine, road-tested used component, offering OEM reliability without the dealership price tag.
Symptoms of a Failing Powertrain Control Module
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or misfiring.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A significant drop in fuel mileage.
- ✔ Failure to pass state emissions tests.
- ✔ The vehicle cranks but will not start.
- ✔ Communication errors with diagnostic scan tools.
This module is a direct replacement for multiple part numbers, including 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. It fits a wide range of popular GM trucks and vans from Chevrolet, GMC, Cadillac, and Isuzu. Please verify your part number and consult the detailed fitment list to ensure compatibility with your specific vehicle.
Installation is straightforward for a knowledgeable DIYer or any professional technician. After purchase, simply provide us with your VIN, and we’ll handle the programming. Once installed, you will need to perform a simple security relearn procedure (often called a Passlock or Passkey relearn) to sync the new module with your vehicle’s anti-theft system. This can typically be done without any special tools and instructions are widely available.
Frequently Asked Questions
Do I need to send you my old PCM?
No, there is no core charge or need to send in your old module. This is an outright purchase, making the process faster and more convenient for you.
What is VIN programming?
VIN programming involves loading your vehicle’s specific factory software and calibration files onto the PCM. This ensures the module works perfectly with your engine, transmission, and all factory-installed options, just as it did when it left the factory.
Is this a difficult part to install?
Physically replacing the PCM is typically simple, involving disconnecting the battery, unplugging a few electrical connectors, and unbolting the module. The most important step after installation is the security relearn procedure, which is required for the vehicle to start. We recommend consulting a repair manual or online resources for your specific model’s procedure.
You mentioned this is a ‘used’ part. Is it reliable?
Absolutely. Each module is sourced from a salvaged vehicle and thoroughly inspected and tested to ensure it is fully functional. By using a genuine OEM part, you are getting a component designed by GM for your vehicle, which often provides superior reliability compared to aftermarket alternatives.
What if this doesn’t fix my problem?
While a faulty PCM is a common issue, proper vehicle diagnosis is key. We guarantee that you will receive a fully functional, correctly programmed module. If the part does not resolve your issue, the problem may lie elsewhere in the vehicle’s systems. We recommend consulting with a qualified technician to ensure an accurate diagnosis.