Restore Peak Performance to Your GM Truck or Van
Is your Chevrolet Express, GMC Savana, Silverado, or Sierra suffering from frustrating and intermittent issues? A faulty Powertrain Control Module (PCM), often called the engine computer, is a frequent cause of poor engine performance, erratic transmission shifting, and mysterious no-start conditions. This vital component is the brain of your vehicle, managing everything from fuel injection and ignition timing to transmission shift points and emissions systems. When it fails, the symptoms can be widespread and difficult to diagnose. This replacement PCM, part number 16265035, is the definitive solution to get your vehicle back on the road and running like new.
Unlike a generic part from a local store, this module is not just a piece of hardware. It’s a complete, ready-to-install solution. Upon purchase, we will use your vehicle’s unique Vehicle Identification Number (VIN) to program the module with the latest, most stable software updates directly from General Motors. This critical step ensures perfect compatibility and communication with all other modules in your vehicle, eliminating the need for an expensive trip to the dealership for programming. It’s designed to be a plug-and-play fix, restoring the precise factory settings your engine and transmission need to operate efficiently.
From the Diagnostic Bay
I once had a 2001 Chevy Express 2500 in the bay that was driving the owner crazy. It would randomly stall at stoplights and had a harsh 1-2 shift that felt like being rear-ended. The owner had already replaced the throttle position sensor and the mass airflow sensor with no improvement. After hooking up the scan tool, I noticed the live data for several sensors was dropping out intermittently. This wasn’t a sensor issue; it was a processing issue. The PCM was failing internally. We installed a VIN-programmed module just like this one, performed the quick security relearn, and the van ran perfectly. It’s a classic case where chasing individual symptoms can be costly, while addressing the root cause—the failing computer—provides a complete and lasting fix.
Common Symptoms of a Failing GM PCM
- ✔ Check Engine Light: The most common indicator, often with communication error codes (U-codes) or multiple, unrelated sensor codes.
- ✔ Rough Idle or Stalling: The engine may run poorly, shake, or stall unexpectedly at intersections or during deceleration.
- ✔ Poor Fuel Economy: An improperly functioning PCM can’t manage the fuel mixture correctly, leading to a noticeable drop in MPG.
- ✔ Hard Shifting or Transmission Problems: You might experience delayed, harsh, or erratic gear changes as the PCM struggles to control the transmission solenoids.
- ✔ Engine Misfires: The computer may fail to command spark or fuel injection correctly, causing misfire codes (P0300-P0308).
- ✔ No-Start Condition: The vehicle may crank but refuse to start, as the PCM isn’t activating the fuel pump or ignition system.
- ✔ Failed Emissions Test: Incorrect engine management will almost certainly lead to a failed smog check.
Diagnosing Your 1999-2002 Savana PCM
Confirming a bad PCM can be tricky, but there are key indicators. First, use a scan tool to check for diagnostic trouble codes. Codes related to PCM internal memory failure, processor faults, or loss of communication with other modules are strong signs. Second, check the wiring harness and connectors leading to the PCM for any signs of corrosion, damage, or loose pins. A poor connection can mimic PCM failure. If the power and ground signals going to the PCM are stable but the module is unresponsive or providing erratic data, it has likely failed. Replacing your faulty computer with this pre-programmed 1999-2002 Savana PCM is the most reliable way to resolve these deep-seated electronic issues and restore your vehicle’s dependability.
Simple Installation Process
Installation is straightforward for anyone with basic mechanical skills. Simply disconnect the vehicle’s battery, locate your existing PCM (often in the engine bay on the driver’s side), disconnect the electrical connectors, and unbolt the module. Install this replacement unit in its place, reconnect the connectors, and finally, reconnect the battery. In most cases, you will need to perform a simple security relearn procedure (also known as a CASE relearn) to sync the new module with your vehicle’s anti-theft system. This procedure can often be done without special tools and instructions are widely available online, or it can be completed by any local mechanic in minutes.
This module is a direct replacement for part numbers: 16263494, 16265035, 8162634940, 218-11787, and 21811787, ensuring broad compatibility across a huge range of GM trucks and vans from the late 90s and early 2000s. Please verify your part number and check the extensive fitment list to ensure this is the correct part for your vehicle.
Frequently Asked Questions
Do I need to program this module?
No. We handle the programming for you before shipment. Simply provide us with your vehicle’s VIN during or after checkout, and the module will arrive with the latest GM software, ready for installation.
Where is the PCM located on my truck or van?
The location varies slightly by model. On most Express and Savana vans, it’s in the LH rear of the engine compartment. On pickups like the Silverado and Sierra, it’s typically on the LH side of the engine compartment, sometimes under the battery tray.
What is a security or CASE relearn procedure?
This is a simple procedure that syncs the new PCM to your vehicle’s security system and crankshaft position sensor. It is required for the vehicle to start and run correctly. The process usually involves turning the key to the ‘ON’ position for a set period of time and can be performed by you or any automotive shop.
How do I provide my VIN?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship your part until we receive this information for programming.
Is this a direct replacement for my original part?
Yes, this PCM is a direct-fit replacement for several original equipment part numbers, including 16263494 and 16265035. It is designed to meet or exceed original factory specifications for a wide range of GM vehicles.