1999-2002 Express 3500 Van PCM 16265035 | Programmed to Your VIN

Restore Your Van’s Reliability and Performance

As a technician with over two decades of experience, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can bring a dependable workhorse like the Chevy Express 3500 to a dead stop. You’re dealing with frustrating symptoms: the engine cranks but won’t start, it runs rough, the transmission shifts erratically, or the check engine light is a permanent fixture on your dash. These aren’t just annoyances; they’re issues that cost you time and money. This isn’t a part you just swap; it’s the brain of your vehicle’s operation, and it needs to be right.

This is your direct-fit, reliable solution. We are offering a Powertrain Control Module, compatible with part number 16265035, that arrives at your door completely programmed for your specific vehicle. We take your vehicle’s VIN and flash the module with the latest, most stable software updates from GM. This critical step ensures all engine and transmission parameters are perfectly calibrated, restoring the smooth performance and fuel efficiency you depend on. Forget about costly towing fees or waiting for a dealership appointment. With this module, you’re getting a solution designed to get your van back on the road and working as hard as you do.

Is Your Van Showing These Classic PCM Failure Signs?

• ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error), P0606 (PCM Processor Fault), or other communication errors.
• ✔ The engine cranks but refuses to start, even with good fuel and spark.
• ✔ Unexplained stalling, rough idling, or engine misfires.
• ✔ A noticeable drop in fuel economy.
• ✔ Harsh or erratic automatic transmission shifting.
• ✔ The anti-theft or security light stays on, preventing the engine from starting.
• ✔ Other modules on the vehicle can’t communicate with the PCM.

Your Straightforward PCM Installation Guide

Installing your pre-programmed 1999-2002 Express 3500 PCM is a manageable job for a confident DIYer or any professional technician. While specific steps can vary slightly by model, here is a general guide.

1. Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
2. Locate the PCM: On most Express/Savana vans, the PCM is located in the engine compartment on the driver’s side, near the rear. On some pickups or SUVs, it may be near the battery tray.
3. Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old PCM. Inspect the pins for any corrosion or damage. Clean them gently with an electrical contact cleaner if necessary.
4. Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new module.
5. Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the original hardware.
6. Reconnect Everything: Firmly plug the electrical connectors into the new PCM until they click into place. Reconnect the negative battery terminal.
7. Perform Security Relearn (If Required): For many GM vehicles of this era, a security relearn procedure is necessary to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating this cycle three times. Consult a service manual for your specific vehicle’s procedure. This step is crucial for the vehicle to start.

Verified Fitment For Your GM Truck or Van

This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following vehicles. Please verify your vehicle is on the list to ensure compatibility.