Restore Peak Performance to Your GM Van or Truck
Is your Chevrolet Express, GMC Savana, or another GM truck giving you headaches? If you’re dealing with a persistent Check Engine Light, erratic shifting, a no-start condition, or poor fuel mileage, a failing Powertrain Control Module (PCM) is often the culprit. As the ‘brain’ of your vehicle, the PCM controls everything from fuel injection and ignition timing to transmission shift points. When it fails, your vehicle’s reliability and performance suffer dramatically. This isn’t just an inconvenience; it can leave you stranded.
We offer a dependable and straightforward solution: a replacement PCM, part number 8162634940, professionally programmed with the latest official GM software updates. We flash the module specifically to your vehicle’s VIN, ensuring it works seamlessly right out of the box. This process eliminates the need for an expensive trip to the dealership for programming, saving you both time and money. By installing this module, you’re not just fixing a problem; you’re restoring your vehicle’s original operating efficiency and addressing potential drivability issues you may not have even realized were related to the old computer.
Case Study: A Tricky Diagnosis
A customer brought in a 2001 Savana 2500 work van that had the shop stumped. The complaint was intermittent harsh shifting, especially from 1st to 2nd gear, but no transmission codes were present. They had already replaced the transmission fluid and filter. My scan tool showed a generic P0700 (Transmission Control System Malfunction) but nothing more specific. After checking all the wiring and connectors between the trans and the PCM, I decided to look at the PCM data itself. I noticed the processor was lagging on command signals. On a hunch, we swapped in one of our VIN-programmed PCMs. The difference was immediate. The shifts became smooth and predictable. The old PCM had an internal processing fault that wasn’t severe enough to set a specific P060x code but was degrading communication with the transmission module. This is a classic example of how a failing PCM can cause symptoms that seem unrelated.
Is Your Vehicle Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Check Engine Light is on, especially with codes like P0601, P0602, P0604, or P0606 (Internal Control Module Memory Check Sum Error).
- ✔ Vehicle will not start or is very difficult to start.
- ✔ Rough or unpredictable engine idling.
- ✔ Poor acceleration and overall engine performance.
- ✔ Decreased fuel economy for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions/smog test.
A Straightforward Guide to Installation
For the DIYer or professional mechanic, installing this 1999-2002 Express 2500 PCM is a manageable job. On most Express and Savana vans, the module is located in the engine compartment on the driver’s side.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On the Express/Savana, find the module mounted to a bracket in the left (driver’s side) rear of the engine compartment.
- Disconnect the Wiring: Carefully unplug the electrical connectors. These GM connectors often have a locking tab or lever that needs to be released before you can pull them straight out. Do not force them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click securely in place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): On many GM vehicles, you must perform a security relearn procedure (often called VATS or Passlock) for the vehicle to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle’s service manual will have the exact procedure.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It fits a wide range of GM trucks and vans. Please verify your vehicle is on this list. Providing your VIN at checkout is essential for us to ensure perfect compatibility and programming.
EXPRESS 1500/2500/3500 VAN 99-02 (gasoline)
SAVANA 1500/2500/3500 VAN 99-02 (gasoline)
ASTRO 99-01 (4.3L)
GMC 1500/2500/3500 PICKUP 99-00 (gasoline)
SIERRA 1500 PICKUP 99-00 (6 cyl)
SILVERADO 1500 PICKUP 99-00 (6 cyl)
S10/S15/SONOMA 98-00 (4.3L)
BLAZER S10/JIMMY S15 98-00
ISUZU HOMBRE 98-00 (4.3L)
SAFARI (GMC) 99-01
TAHOE 99-00
YUKON 99-00
ESCALADE 99-00
BRAVADA 98-00
ENVOY 98-00
SUBURBAN 1500/2500 99 (gasoline)
Note: Some models require matching the ID number 16263494. Please check your original part.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is crucial. It allows us to access the exact GM calibration file for your vehicle’s specific engine, transmission, and options. This ensures the 1999-2002 Express 2500 PCM works perfectly upon installation, without needing a dealer visit.
Is this a plug-and-play part?
Yes, because we program it to your VIN, it is ready to install. However, many GM vehicles of this era require a security relearn procedure (VATS/Passlock) after installation to enable the fuel system. This is a simple procedure you can do yourself with just the ignition key.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the electronic functions of the transmission. If your hard shifting or slipping is caused by a faulty computer command, a new PCM will resolve it. If the problem is a mechanical failure inside the transmission, this part will not fix that.
What if my part number is slightly different?
This module is a direct replacement for several part numbers, including 16263494, 16265035, and others listed. As long as your vehicle is on the compatibility list and you provide your VIN, we will ensure you receive the correct, compatible hardware and software.