Restore Peak Performance to Your GMC Safari or GM Vehicle
Is your trusty GMC Safari, Chevy Astro, or another GM truck from that era suffering from perplexing issues like stalling, poor fuel economy, or a persistent check engine light? As a technician with over two decades of experience, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can be the hidden culprit behind a host of frustrating problems. This isn’t just a replacement part; it’s a direct solution to restore your vehicle’s factory-spec performance and reliability.
This module, part number 16265035, is the brain of your vehicle’s engine and transmission. We take the guesswork and hassle out of the repair by programming it specifically to your vehicle’s VIN before we ship it. This means it arrives loaded with the latest GM software updates, ensuring optimal communication between all your vehicle’s systems. You get a component that’s ready for installation right out of the box, saving you a costly trip to the dealership for programming.
From the Diagnostic Bay: The Ghost in the Machine
I remember a 2000 GMC Safari that came into my shop with a classic case of what the owner called “the ghost.” It would run perfectly fine for days, then suddenly refuse to start. Other times, the transmission would shift harshly for no reason. The owner had already replaced the fuel pump and spark plugs with no success. After hooking up my scanner, I didn’t see any obvious sensor codes, but a deeper dive revealed intermittent communication loss and a tell-tale P0601 (Internal Control Module Memory Check Sum Error). The original PCM’s internal processor was failing. We installed a VIN-programmed module just like this one, and the van ran flawlessly. It’s a perfect example of how targeting the root cause with the right part saves time, money, and a lot of headaches.
Is Your GM Vehicle Showing These Symptoms?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need.
- ✔ Check Engine Light is illuminated with codes like P0601, P0603, P0604, or P0605.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle stalls intermittently, either while driving or at idle.
- ✔ Failure to pass an emissions or smog test.
- ✔ Loss of power or sluggish acceleration.
Your Straightforward Installation Guide
Installing your new 1999-2001 GMC Safari PCM is a manageable job for a confident DIYer. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On most GMC Safari and Chevy Astro vans, the PCM is located on the driver’s side of the engine compartment, near the battery. On other GM trucks and vans, it may be on the left-hand (LH) or right-hand (RH) side of the engine bay or rear engine compartment. Consult your owner’s manual if unsure.
- Disconnect the Wiring Harnesses: Carefully unclip and disconnect the electrical connectors from the old PCM. These connectors have locking tabs that may need to be gently pried or squeezed to release. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the mounting hardware, as you will need it to install the new module.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket using the original hardware. Ensure it is secure.
- Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click into place. Reconnect the negative battery terminal.
- Perform a Security Relearn (If Necessary): While this module comes programmed, some GM vehicles require a simple key-cycle security relearn procedure to sync with the anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times before starting the engine.
Verified Compatibility for Your GM Vehicle
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 match your vehicle and options carefully.
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
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations specific to your vehicle’s engine, transmission, and options. This ensures a perfect match and seamless operation upon installation.
Is this a simple plug-and-play installation?
Yes, for the most part. Because we program it to your VIN, it’s ready to be installed. Some vehicles may require a simple ‘security relearn’ procedure, which can be done without any special tools by cycling the ignition key.
Will this fix my check engine light?
If the check engine light is on due to an internal PCM fault (like DTC P0601), this module will resolve the issue. We always recommend having a professional mechanic diagnose the codes first to ensure the PCM is the root cause.
What if I have the wrong part number?
This module replaces several part numbers, including 16263494 and 8162634940. As long as your vehicle is on the compatibility list, this part will work. The VIN programming ensures it functions correctly for your specific application.
Do I need to send my old PCM back?
No core charge or return is required for this purchase. You can recycle your old module locally.