Is your reliable Chevy or GMC workhorse suddenly giving you headaches? If you’re dealing with a persistent Check Engine Light, unpredictable stalling, poor fuel economy, or erratic engine behavior, the problem often traces back to a failing Powertrain Control Module (PCM). As the central computer of your vehicle, a faulty PCM can create a cascade of frustrating issues. I’ve seen it countless times in my 20+ years in the shop—a perfectly good engine held back by a failing electronic brain.
This isn’t just a replacement part; it’s a direct solution. We offer a dependable Powertrain Control Module for your 1999-2000 Chevrolet 3500 Pickup and other compatible GM vehicles. The critical difference? We flash this module with the latest official GM software updates, programmed specifically to your vehicle’s VIN before it ever leaves our facility. This means no expensive trips to the dealership for programming. You get a component that’s ready for installation right out of the box, restoring the performance and reliability you depend on.
From the Diagnostic Bay
I remember a 2000 Chevy 3500 with the 5.7L that came into the bay with a ghost of a problem. The owner, a contractor, said it would run fine for an hour, then stall at a stoplight and refuse to restart for 15 minutes. No consistent codes, just pure frustration. After checking fuel pressure, spark, and all the usual suspects, we focused on the PCM. On these trucks, heat soak can cause internal solder joints in the module to fail intermittently. We swapped in a pre-programmed PCM, and the problem vanished instantly. It’s a classic failure mode for this 1999-2000 Chevrolet 3500 PCM, and a new module is the only certain fix.
Is Your Truck’s Brain Failing? Common Symptoms
A failing PCM can manifest in various ways. If your vehicle is showing any of these signs, the PCM is a likely culprit. Look out for:
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Stalling for no apparent reason, especially when warm
- ✔ Complete no-start condition where the engine cranks but won’t fire
- ✔ Noticeable decrease in fuel efficiency
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Diagnostic Trouble Codes (DTCs) stored, such as P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault)
Straightforward Swap: Your PCM Installation Guide
Replacing the PCM on these GM trucks is a job most DIYers can handle with basic tools. Follow these steps for a successful installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the Module: On most 1999-2000 Chevrolet 3500 Pickups, the PCM is located in the engine compartment on the driver’s side, often near the battery or firewall.
- Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released before they can be pulled off.
- Remove the Old PCM: Unbolt the module from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely fasten it. Re-attach the wiring harness connectors, ensuring they click firmly into place.
- Reconnect and Start: Reconnect the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves turning the key to the ‘On’ position for 10-15 minutes. In some cases, a CASE (Crankshaft Angle Sensor Error) relearn may be necessary with a capable scan tool for optimal performance.
Verified Vehicle Compatibility List
This module is a direct-fit replacement for units with part numbers 16263494, 16265035, 8162634940, 218-11787, or 21811787. Please verify your part number or use the fitment list below. After purchase, simply provide us with your VIN for programming.
CHEVROLET 2500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
EXPRESS 1500 VAN 00 Electronic Control Module; (LH rear engine compartment)
EXPRESS 2500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
EXPRESS 3500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
SAVANA 1500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), ID 16263494
ASTRO 00-01 Electronic Control Module; (LH front by battery), ID 16263494
GMC 3500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
EXPRESS 2500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
S10/S15/SONOMA 99-00 Electronic Control Module; (RH front engine compartment), 4.3L
SAVANA 1500 VAN 00 Electronic Control Module; (LH rear engine compartment)
ASTRO 99 Electronic Control Module; (LH front by battery), (4.3L), ID 16263494
ISUZU HOMBRE 99-00 Electronic Control Module; (RH front engine compartment), 4.3L (6 cylinder)
SAFARI (GMC) 99-01 Electronic Control Module; (LH front by battery), ID 16263494
SAVANA 3500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
EXPRESS 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 16263494
GMC 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16263494
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/build date opt ZN4
GMC 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16263494
SAVANA 3500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
SAVANA 3500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
TAHOE 00 Electronic Control Module; Classic style (LH front engine compartment)
YUKON 99 Electronic Control Module; (LH engine compartment), ID 16263494
ESCALADE 99 Electronic Control Module; (LH front engine compartment), ID 16263494
ESCALADE 00 Electronic Control Module; (LH front under battery)
EXPRESS 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/build date opt ZN4
YUKON 00 Electronic Control Module; (LH front under battery), Denali
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/build date opt ZN4
CHEVROLET 3500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
ENVOY 99-00 Electronic Control Module; (RH front engine compartment)
EXPRESS 1500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), ID 16263494
EXPRESS 3500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
GMC 3500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/extended build date opt ZN4
SIERRA 1500 PICKUP 99-00 Electronic Control Module; (LH front under battery), 6 cylinder
SAVANA 2500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
SUBURBAN 1500 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16263494
EXPRESS 3500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
GMC 2500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
SILVERADO 1500 PICKUP 99-00 Electronic Control Module; (LH front under battery), 6 cylinder
SUBURBAN 2500 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
BLAZER S10/JIMMY S15 99-00 Electronic Control Module; (RH front engine compartment)
CHEVROLET 3500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
SAVANA 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 16263494
TAHOE 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
BRAVADA 99-00 Electronic Control Module; (RH front engine compartment)
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16263494
SAVANA 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
SAVANA 2500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/build date opt ZN4
GMC 2500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software calibration that GM specified for your truck’s engine, transmission, and options. This ensures perfect compatibility and optimal performance.
Is this a simple plug-and-play installation?
Yes, for the most part. The module arrives programmed to your VIN. After installation, you may need to perform a simple, no-tool security relearn procedure. On some vehicles, a CASE relearn with a scan tool is recommended to clear certain codes and ensure smooth operation.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like codes P0601-P0606), this replacement will resolve the issue. However, you should always diagnose other potential sensor or wiring issues first.
Is this a new or used part?
This is a high-quality, inspected, and tested component that is guaranteed to function to OE specifications. Each unit is programmed with the latest software and verified before shipment.
What if I have questions during installation?
Our team of experienced technicians is here to help. If you run into an issue or have a question, feel free to contact us for support. We’re committed to helping you get your vehicle back on the road.