Is Your 1999-2000 Sierra or Silverado Running Rough? It Could Be The PCM.
If you’re dealing with frustrating and unpredictable issues in your GM truck or van, the Powertrain Control Module (PCM) is a likely culprit. As a technician with over two decades of experience under the hood, I’ve seen these exact modules cause headaches that seem to come out of nowhere. The PCM is the electronic brain of your engine and transmission, and when it starts to fail, it can create a cascade of problems that are often misdiagnosed.
These vehicles are workhorses, but the electronics are now over 20 years old. The constant heat cycles, engine vibration, and potential moisture exposure take their toll on the sensitive internal circuits of the PCM. This can lead to intermittent connections and component failure inside the module itself.
Common Symptoms of a Failing GM PCM:
- โ Check Engine Light is on with various communication or sensor codes.
- โ The engine cranks but refuses to start.
- โ Unexplained stalling, especially when coming to a stop or at idle.
- โ Harsh or erratic automatic transmission shifting.
- โ Noticeable decrease in fuel economy.
- โ The anti-theft or security light stays on, preventing the engine from starting.
From the Shop Floor: A Real-World Diagnosis
“A customer’s 2000 Silverado 1500 with the 4.3L V6 came in last week with a classic no-start condition. It would crank all day but never fire up. The fuel pump was working, and it had spark, but the injector pulse was non-existent. After confirming all power and ground circuits to the PCM were solid (a critical first step!), we connected our scan tool and found we couldn’t communicate with the module at all. This is a tell-tale sign of internal PCM failure. We installed one of our pre-programmed modules, performed the quick security relearn, and the truck fired right up and ran perfectly. The original PCM had simply given up after years of service.”
The Guaranteed Solution: A VIN-Programmed PCM
Don’t just swap in a used module from a junkyard. It won’t have the correct software for your vehicle’s specific options, and it won’t have the critical anti-theft data matched. Our service solves this problem completely. When you order, we require your vehicle’s 17-digit VIN. Using this, we flash the module with the latest, most stable software release from General Motors. This ensures the PCM is a perfect match for your truck’s engine, transmission, and other factory-installed systems.
- โ Plug & Play Ready: Arrives programmed to your specific VIN.
- โ Latest GM Software: We load the newest updates, which can correct factory drivability issues.
- โ No Dealer Visit Needed: Avoids expensive and time-consuming dealer programming.
- โ Direct Replacement: Matches part numbers 16263494, 16265035, 8162634940, and 218-11787.
Important Installation Note
After installing this module, you will likely need to perform a simple security relearn procedure. This process syncs the new PCM to your vehicle’s anti-theft system and ignition key. It typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating the cycle two more times. This is a straightforward procedure that can be done in your driveway and does not require a special scan tool. This final step is essential for the vehicle to start and run with the new module.