Restore Your Van’s Performance and Reliability
Is your Chevrolet Express or GMC Savana van running rough, stalling unexpectedly, or showing a persistent check engine light? As a technician with over two decades of experience, I’ve seen these symptoms countless times, and they often point directly to a failing Powertrain Control Module (PCM). The PCM is the brain of your vehicle, managing everything from fuel delivery and spark timing to transmission shifts. When it starts to fail, it can cause a cascade of frustrating and hard-to-diagnose issues. This isn’t just an inconvenience; it can affect your work, your safety, and your fuel budget.
This isn’t just a replacement part; it’s a complete solution. We take the guesswork and extra cost out of the equation by programming this PCM specifically for your vehicle using your VIN. This means it arrives at your door with the latest GM software updates, ready for a straightforward installation. You get a reliable fix that restores your vehicle’s original performance and efficiency, without the need for an expensive trip to the dealership for programming. This is the definitive solution for your 1999-2002 Express 3500 Van PCM and other compatible GM vehicles.
From the Diagnostic Bay: The Phantom Misfire
I remember a customer with a 2001 Savana 2500 work van that had a persistent, random misfire code (P0300) and rough idle. He’d already spent hundreds replacing spark plugs, wires, the cap, and the rotor, but the problem always returned. His scanner showed nothing else wrong. When it got to my bay, I checked the basics, and they were fine. The tell-tale sign was the inconsistency. On a hunch, I monitored the injector pulse data and saw erratic signals on multiple cylinders. This wasn’t a mechanical issue; it was a logic failure inside the computer. We installed a correctly programmed PCM, and the van ran perfectly. It’s a classic case where chasing parts costs more than correctly diagnosing the root cause—the failing PCM.
Common Signs of a Failing GM PCM
If your vehicle’s computer is on its way out, you’ll likely notice one or more of these issues. A failing 1999-2002 Express 3500 Van PCM can be the hidden cause behind many performance problems. Check if any of these sound familiar:
- âś” Check Engine Light is on with codes like P0601, P0604, or P0606 (Internal Module Failure).
- âś” Vehicle refuses to start or stalls for no reason.
- âś” Harsh or erratic automatic transmission shifting.
- âś” A noticeable drop in fuel economy.
- âś” Engine misfires or runs rough, even after a tune-up.
- âś” Communication errors with your OBD-II scan tool.
A Straightforward Guide to Installation
Replacing the PCM on these GM vans and trucks is a job most DIYers can handle with basic tools. Because we program it beforehand, you skip the most complicated step. Here’s a general guide:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system to fully discharge.
- Locate the PCM: On Express/Savana vans, it’s typically in the LH rear of the engine compartment. On trucks, it’s often on the LH side, sometimes near or under the battery tray.
- Disconnect the Harnesses: Carefully unclip and remove the large electrical connectors. These have locking tabs, so be gentle to avoid breaking them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held by a few small bolts.
- Install the New PCM: Mount your new, pre-programmed PCM in the same location and secure it with the bolts.
- Reconnect Everything: Firmly plug the electrical harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You may need to perform a simple security relearn procedure. Typically, this involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times before starting the engine. This allows the vehicle’s anti-theft system to recognize the new PCM.
Verified Vehicle Compatibility
This module, identified by part number 16263494, is a direct-fit replacement for a wide range of GM vehicles. It is also compatible with part numbers 16265035, 8162634940, and 218-11787. Please verify your vehicle is on the list below. Providing your VIN at checkout is essential to ensure we load the correct software for your specific model, year, and options, guaranteeing a perfect match for a 1999-2002 Express 3500 Van PCM or other listed vehicle.
EXPRESS 1500 VAN 99-02
EXPRESS 2500 VAN 99-02 (gasoline)
EXPRESS 3500 VAN 99-02 (gasoline)
SAVANA 1500 VAN 99-02
SAVANA 2500 VAN 99-02 (gasoline)
SAVANA 3500 VAN 99-02 (gasoline)
ASTRO 99-01 (4.3L)
GMC 1500 PICKUP 99 (5.0L, 5.7L)
GMC 2500 PICKUP 99-00 (gasoline)
GMC 3500 PICKUP 99-00 (gasoline)
S10/S15/SONOMA 98-00 (4.3L)
BLAZER S10/JIMMY S15 98-00
BRAVADA 98-00
ENVOY 98-00
ISUZU HOMBRE 98-00 (4.3L)
SAFARI (GMC) 99-01
TAHOE 99-00 (Classic style)
YUKON 99-00 (incl. Denali)
ESCALADE 99-00
SIERRA 1500 PICKUP 99-00 (6 cyl)
SILVERADO 1500 PICKUP 99-00 (6 cyl)
SUBURBAN 1500/2500 99 (gasoline)
Note: Some 1998 models require build date option ZN4. Please verify your part number.
Why do you need my VIN?
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is crucial. It allows us to access the exact GM factory calibration file for your vehicle’s specific engine, transmission, and options. This ensures the PCM works perfectly out of the box, controlling all systems as the manufacturer intended.
Is this a simple plug-and-play installation?
Yes, for the most part. Because we pre-program the module, you do not need a dealer scan tool. After physical installation, you will likely need to perform a simple security relearn procedure, which takes about 30 minutes and involves cycling the ignition key. We provide instructions for this process.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like codes P0601-P0606), then yes, this will resolve the issue. However, if the light is on due to a faulty sensor or other component, you will still need to repair that underlying problem. This PCM will restore correct diagnostic functions so you can accurately identify any other issues.
What if my part number isn’t an exact match to 16263494?
This module is a direct replacement for several part numbers, including 16265035 and 8162634940. As long as your vehicle is on our compatibility list and you provide a valid VIN, we will ensure the module is programmed correctly to function as a proper replacement for your original unit.