Restore Peak Performance to Your GM Truck or Van
Is your 1999-2000 Chevrolet Tahoe, Suburban, or other compatible GM vehicle suffering from perplexing engine problems? A faulty Powertrain Control Module (PCM) is often the hidden culprit behind issues like a persistent Check Engine Light, rough idling, stalling, poor fuel economy, or erratic transmission shifting. This vital component is the central computer of your vehicle, managing everything from fuel injection and ignition timing to transmission operation. When it fails, the entire system’s performance and reliability are compromised.
This replacement Powertrain Control Module, part number 21811787 (also compatible with 16263494 and 16265035), is the definitive solution to get your truck back on the road. We take the guesswork and hassle out of the repair process. Before we ship the module, we program it specifically to your vehicle using your VIN. This ensures it arrives loaded with the latest official GM software updates, making it a true plug-and-play replacement. You won’t need to pay for expensive programming services at a dealership or specialized shop.
We had a 1999 GMC Sierra 1500 come into the shop with a complaint of intermittent stalling and a Check Engine Light that just wouldn’t stay off. The owner had already replaced the throttle position sensor and the mass airflow sensor, but the problem persisted. After connecting our scan tool, we noticed erratic data streams coming from multiple sensors, but the sensors themselves tested fine. This pointed us directly to the PCM. The internal circuitry was failing, corrupting the signals it was processing. We installed a VIN-programmed PCM just like this one, and the truck immediately ran like new. The customer was thrilled to have a reliable vehicle again after weeks of chasing the wrong parts.
Symptoms of a Failing 1999-2000 Tahoe PCM
If you’re experiencing any of the following issues, your PCM could be the cause. Replacing it can restore your vehicle’s drivability and efficiency.
- ✔ Check Engine Light: The light is on, and you may have codes related to multiple sensors, communication errors (U-codes), or internal module failure (P06xx codes).
- ✔ Engine Performance Problems: Noticeable loss of power, hesitation during acceleration, rough or unstable idle, and frequent stalling.
- ✔ No-Start Condition: The engine cranks but refuses to start, often due to a lack of fuel injector pulse or spark command from the PCM.
- ✔ Poor Fuel Economy: A sudden and unexplained drop in your vehicle’s gas mileage as the PCM fails to manage the engine efficiently.
- ✔ Transmission Shifting Issues: Harsh shifting, delayed engagement, or getting stuck in one gear (limp mode) can be caused by a faulty PCM failing to communicate with the transmission controller.
- ✔ Failed Emissions Test: Incorrect air/fuel mixture control can lead to an automatic failure at the emissions station.
This module is a direct-fit replacement for a wide range of popular GM trucks and vans from the late 90s and early 2000s, including the Chevrolet Silverado, Express, S10, and GMC Sierra, Savana, and Yukon. Please verify your original part number and check the detailed fitment list to ensure compatibility. By providing us with your VIN, you guarantee that the 1999-2000 Tahoe PCM you receive is perfectly matched to your vehicle’s specific configuration, ensuring a smooth installation and immediate results.
Frequently Asked Questions
Do I need to have this PCM programmed by a dealer?
No. This is the primary benefit of our service. We program the module to your vehicle’s specific VIN before shipping it to you. It will arrive ready for installation, requiring no additional programming.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM stands for Powertrain Control Module. A PCM is a more advanced controller that typically manages both the engine and the transmission functions, which is common in vehicles like the 1999-2000 Tahoe.
How do I provide my VIN number?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship the module until we receive this information, as the programming is essential for the part to function correctly.
Is any other procedure required after installation?
In some cases, a security relearn procedure (often called a CASE relearn or Passlock relearn) may be necessary. This is a simple procedure that can typically be done without special tools and involves a sequence of key cycles. Instructions are widely available online for your specific model.
Will this fix my Check Engine Light?
If the Check Engine Light is caused by an internal failure of your existing PCM, then yes, this part will resolve the issue. However, it’s crucial to ensure that the codes are not being caused by faulty sensors or wiring. A proper diagnosis is always recommended before replacing a control module.