If you’re dealing with frustrating, hard-to-diagnose issues on your GM truck or van, the Powertrain Control Module (PCM) is often the culprit. As the central computer for your engine and transmission, a failing PCM can cause a host of problems that can leave even seasoned mechanics scratching their heads. This isn’t just a replacement part; it’s a complete, ready-to-install solution for your 1998-2000 S10, Sonoma, or other compatible GM vehicle. We take the guesswork and extra expense out of the repair by programming the module to your specific Vehicle Identification Number (VIN) before it ever leaves our facility. This ensures it communicates perfectly with your vehicle’s systems right out of the box.
A Technician’s Notebook
I remember a 1999 GMC Jimmy with the 4.3L V6 that came into the shop with the most bizarre symptoms. The customer complained of intermittent stalling at stoplights and occasional harsh shifting, but the Check Engine Light wasn’t always on. When it was, we’d get a generic communication error. We checked grounds, tested sensors, and couldn’t find a consistent fault. On a hunch, we swapped in a known-good PCM. The problems vanished instantly. The original module’s internal processor was failing under specific heat and load conditions, a classic sign of PCM failure that a simple code reader won’t always pinpoint.
Is Your Vehicle Showing These Telltale Signs?
A faulty PCM can manifest in many ways. If you’re experiencing any of the following, your engine computer may be the root cause:
- âś” Unexplained Check Engine Light illumination, especially with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- âś” Engine stalling, stumbling, or rough idling for no apparent reason.
- âś” A noticeable drop in fuel economy.
- âś” Harsh or erratic automatic transmission shifting.
- âś” The engine cranks but refuses to start (no-start condition).
- âś” Failure to pass an emissions or smog test.
Your Straightforward Installation Guide
Replacing the PCM on these vehicles is a job most DIYers can handle in their own driveway. Our VIN programming service means you won’t need a trip to the dealer for expensive flashing. Just follow these general steps:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most S10/Sonoma/Blazer models, it’s on the right-hand (passenger) side of the engine compartment. On full-size trucks and vans, it’s often on the left-hand side, sometimes under the battery tray.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old module. These connectors are color-coded to prevent mix-ups.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM into the bracket and securely re-fasten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the correct ports on the new module. Reconnect your negative battery terminal.
- Perform Security Relearn (If Needed): Some vehicles may require a simple key-cycle security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. We include specific instructions if this is necessary for your vehicle.
Guaranteed Fitment for Your GM Truck & Van
This module, part number 16263494, is a direct replacement for a wide range of GM vehicles. We guarantee compatibility when you provide your VIN. It is a direct fit for the following models, and is also compatible with part numbers 16265035, 8162634940, 218-11787, and 21811787.
This part will fit many GM models including the 1998-2000 S10 Sonoma PCM, Blazer, Jimmy, Bravada, as well as full-size trucks and vans like the Silverado, Sierra, Tahoe, Yukon, Express, and Savana. Please use the fitment chart to confirm your specific year, model, and engine combination. Verifying the ID number on your original module is the best way to ensure a perfect match.
Frequently Asked Questions
Is this module truly plug-and-play?
Yes! Because we program it with your vehicle’s VIN and the latest GM software updates before shipping, it arrives ready for installation. In most cases, no further programming is required.
Why do you need my VIN?
Your VIN (Vehicle Identification Number) allows us to load the exact software and calibrations your specific vehicle requires. This ensures proper engine, transmission, and emissions system operation.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls transmission shift points and line pressure. If the module is faulty, it can cause harsh or erratic shifting. Replacing a bad PCM often resolves these issues.
Where do I find the part number on my old PCM?
The part number is typically on a sticker affixed to the metal case of the module. Look for a prominent number, often beginning with ‘162’ for this series. Matching this number is a great way to confirm compatibility.
Do I need to send my old part back?
No core charge or return is required for this part, saving you time and the hassle of return shipping.