Is Your Late 90s GM Truck or Van Running Rough?
If your 1999-2000 GMC Yukon, Chevy Silverado, Tahoe, or Express van is experiencing perplexing issues like a persistent check engine light, erratic transmission shifting, stalling, or a complete no-start condition, the culprit is often a failing Powertrain Control Module (PCM). As the central computer, the PCM is responsible for managing everything from fuel injection and ignition timing to transmission shift points and emissions systems. When it begins to fail, it can create a cascade of problems that are often misdiagnosed, leading to wasted time and money on unnecessary repairs.
From the Diagnostic Bay
I remember a 2000 Chevy Silverado 1500 that came into the shop towed on a flatbed. The owner had already replaced the fuel pump, crank sensor, and ignition coil, but it would still crank without starting. After checking for fuel pressure and spark, which were intermittently present, we hooked up our high-level scanner. Communication with the PCM was spotty at best. We checked the main power and ground circuits to the module, which were solid. That’s a classic sign of internal PCM failure on these GMT800 platform precursors. We installed one of our pre-programmed modules, performed a quick security relearn, and the truck fired up on the first try and ran perfectly. The owner was frustrated he’d spent hundreds on other parts first, but relieved to finally have the correct solution.
Symptoms of a Failing GM Powertrain Control Module
- ✔ Persistent Check Engine Light (CEL) with communication error codes.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Vehicle refuses to start despite having spark and fuel pressure.
- ✔ Noticeable decrease in fuel economy.
- ✔ Failure to pass state emissions testing.
- ✔ Other modules on the vehicle network (like the ABS or BCM) reporting a loss of communication with the PCM.
A Plug-and-Play Solution for Your 1999-2000 Yukon PCM
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork out of the repair by pre-programming this module specifically for your vehicle using the VIN you provide. This process ensures that the module has the correct software and calibrations for your truck’s specific engine, transmission, and options package. We load the latest available updates from General Motors, which can often resolve inherent factory bugs and improve overall vehicle operation. By matching the software to your VIN, we ensure a seamless installation process, restoring your vehicle’s factory performance and reliability.
This module is a direct replacement for several original equipment part numbers, including 16263494, 16265035, and 8162634940. Please verify your part number or consult the extensive fitment list to confirm compatibility with your specific make, model, and year.
Frequently Asked Questions
Do I need to do any programming after I receive this PCM?
No, this module comes pre-programmed to your vehicle’s VIN. However, on most of these GM vehicles, you will need to perform a simple security relearn procedure, also known as the Passlock or VATS relearn. This procedure can be done without any special tools and typically involves turning the key on and off in a specific sequence. Instructions are readily available online or we can provide them.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) contains critical information about your truck’s original build, including engine size, transmission type, emissions equipment, and other electronic options. Programming the PCM with your VIN ensures all these systems are controlled correctly, just as they were from the factory.
Is this a simple plug-and-play installation?
Yes, for the most part. Once you perform the security relearn, the module is ready to go. The physical installation involves disconnecting the battery, unplugging the electrical connectors from the old PCM, unbolting it from its bracket, and installing the new one in its place. It’s a straightforward job for a DIY mechanic.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this part will resolve the issue. It’s crucial to have your vehicle properly diagnosed to confirm the PCM is the root cause. Common PCM-related codes include communication errors (U-codes) or internal processor fault codes (P06xx series).
What is the difference between a PCM, ECM, and ECU?
The terms are often used interchangeably. ECU (Electronic Control Unit) is a generic term. ECM (Engine Control Module) typically only controls engine functions. PCM (Powertrain Control Module) is the most common term for these GM vehicles, as it controls both the engine and the transmission functions in one integrated unit.