Restore Peak Performance to Your GM Van or Truck
Is your Chevrolet Express or GMC Savana suffering from frustrating, hard-to-diagnose issues? A failing Powertrain Control Module (PCM) is often the culprit behind problems that new sensors and parts can’t seem to fix. As the central computer for your engine and transmission, its health is critical. This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take your vehicle’s VIN and program this module with the latest official GM software updates, ensuring it communicates flawlessly with your specific vehicle the moment you plug it in. Stop chasing electronic gremlins and get a definitive fix with this professionally programmed 1999-2002 Express 1500 PCM.
A Technician’s Notebook: The Intermittent No-Start
I had a 2001 Savana 2500 in the shop that was a nightmare for its owner, a local contractor. It would randomly refuse to start, but only after it was hot. No check engine light, no obvious codes. He’d already replaced the battery, starter, and crank sensor. After checking fuel pressure and spark during a no-start event, I noticed the injector pulse was completely gone. That pointed straight to the PCM. The internal board was likely developing a micro-fracture when it heated up, cutting power to the injector driver circuit. We installed a VIN-programmed PCM just like this one, and the van has been starting reliably ever since. It’s a classic failure I’ve seen dozens of times on these workhorse vans.
Common Signs of a Failing PCM
- âś” Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- âś” Your vehicle fails to start or stalls intermittently for no apparent reason.
- âś” Noticeable decrease in fuel economy.
- âś” Harsh or erratic automatic transmission shifting.
- âś” Engine misfires, runs rough, or hesitates on acceleration.
- âś” Communication errors with your OBD-II scan tool.
A Straightforward Guide to Installation
Replacing your 1999-2002 Express 1500 PCM is a job most DIYers can handle in under an hour. Since this module arrives programmed, you won’t need any special scan tools for setup.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before working on any electronic components.
- Locate the PCM: On Express and Savana vans, the PCM is typically found in the engine compartment on the driver’s side, near the rear. On pickups and SUVs, it’s often on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unplug the electrical connectors from the old module. They have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Plug the wiring harnesses firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Security Relearn (If Needed): For many of these GM vehicles, you may need to perform a simple security relearn procedure. Turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle three times. The vehicle should then start and run normally.
Will This Fit My Vehicle?
This module is a direct-fit replacement for a wide range of GM trucks, vans, and SUVs. It is compatible with original part numbers 16263494, 16265035, 8162634940, and 21811787. Please verify your vehicle is on the list below. After purchase, we will contact you for your VIN to ensure perfect programming.
EXPRESS 1500 VAN 99-02 (LH rear engine compartment)
EXPRESS 2500 VAN 99-02 (Gasoline, LH rear engine compartment)
EXPRESS 3500 VAN 99-02 (Gasoline, LH rear engine compartment)
SAVANA 1500 VAN 99-02 (LH rear engine compartment)
SAVANA 2500 VAN 99-02 (Gasoline, LH rear engine compartment)
SAVANA 3500 VAN 99-02 (Gasoline, LH rear engine compartment)
ASTRO 99-01 (LH front by battery)
SAFARI (GMC) 99-01 (LH front by battery)
BLAZER S10/JIMMY S15 98-00 (RH front engine compartment)
S10/S15/SONOMA 98-00 (4.3L, RH front engine compartment)
ISUZU HOMBRE 98-00 (4.3L, RH front engine compartment)
BRAVADA 98-00 (RH front engine compartment)
ENVOY 98-00 (RH front engine compartment)
CHEVROLET 1500 PICKUP 99 (5.0L & 5.7L, LH engine compartment, ID 16263494)
CHEVROLET 3500 PICKUP 99-00 (Gasoline, LH front engine compartment)
GMC 1500 PICKUP 99 (5.0L & 5.7L, LH engine compartment, ID 16263494)
GMC 2500 PICKUP 99-00 (Gasoline, LH front engine compartment)
GMC 3500 PICKUP 99-00 (Gasoline, LH front engine compartment)
SILVERADO 1500 PICKUP 99-00 (4.3L V6, LH front under battery)
SIERRA 1500 PICKUP 99-00 (4.3L V6, LH front under battery)
TAHOE 99-00 (Gasoline, Classic style, LH front engine compartment)
YUKON 99-00 (Includes Denali, LH engine compartment/under battery)
SUBURBAN 1500/2500 99 (Gasoline, LH front engine compartment, ID 16263494)
ESCALADE 99-00 (LH front engine compartment/under battery)
Note: Some 1998 models require build date option ZN4. Please verify your part number.
What does ‘VIN Programmed’ mean?
What does ‘VIN Programmed’ mean?
It means we load the module with the specific software and calibration file for your exact vehicle using your 17-digit Vehicle Identification Number (VIN). This ensures the PCM works perfectly with your engine, transmission, and options, just like the original part from the factory. It eliminates the need for an expensive trip to the dealership for programming.
Is this a simple plug-and-play installation?
Yes, for the vast majority of vehicles. Once you install the module, you may need to perform a simple key-cycle security relearn procedure, which takes about 30 minutes and requires no tools. We include instructions for this common step.
How do I provide my VIN?
After you complete your purchase, we will send you an email requesting your vehicle’s VIN. You can also add it to the ‘notes’ section during checkout. We cannot ship your part until we have the VIN to program it correctly.
Will this fix my specific problem?
If your vehicle’s issues match the common symptoms of PCM failure and you’ve ruled out other components (like sensors or wiring), this module is very likely the solution. A proper diagnosis is always recommended, but a faulty PCM is a frequent cause for the symptoms listed above in these GM models.