Restore Peak Performance to Your GM Truck or Van
Is your trusty GMC Yukon, Chevy Silverado, or Express van suddenly acting up? If you’re dealing with a persistent Check Engine Light, erratic engine behavior, or transmission shifting problems, the root cause is often a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM governs everything from fuel injection and ignition timing to automatic transmission shifts. When it falters, the entire vehicle’s performance suffers. This isn’t just an annoyance; it can affect fuel economy, reliability, and even your ability to pass an emissions test.
This replacement PCM, part number 16265035, is the definitive solution. We take the guesswork and hassle out of the repair by pre-programming the module 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 factory operation without an expensive trip to the dealership for programming.
A Technician’s Notebook: The Intermittent No-Start Nightmare
I remember a 2000 GMC Yukon that came into my bay with a ghost of a problem. The owner said it would randomly refuse to start, but only after it was fully warmed up. No codes, no warning lights. We checked the fuel pump, crank sensor, and ignition system—all tested fine. After hours of diagnostics, we noticed the 5-volt reference signal to the sensors would drop out during the no-start condition. That pointed directly to an internal failure in the PCM. Heat soak was causing a hairline crack on the circuit board to expand, breaking the connection. Swapping in a quality, pre-programmed PCM like this one solved the problem instantly. It’s a classic failure mode on these older GM workhorses.
Is Your Truck or Van Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your vehicle’s computer needs attention:
- âś” Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- âś” Engine stalling, stumbling, or misfiring for no apparent reason.
- âś” Harsh or erratic automatic transmission shifting.
- âś” A sudden, unexplainable drop in fuel economy.
- âś” Complete no-start or intermittent starting condition.
- âś” Failure to communicate with a diagnostic scan tool.
A Straightforward Guide to Installation
One of the biggest benefits of this module is its simple installation process. Because we handle the programming, you can perform the swap yourself with basic hand tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these GM trucks and vans, the PCM is located in the engine compartment, often on the driver’s side fender well or near the battery.
- Disconnect the Old Module: Carefully unplug the electrical harness connectors. They have locking tabs that need to be released. Once unplugged, unbolt the old PCM from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed PCM into place and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn: Most of these GM vehicles require 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. On the fourth try, the vehicle should start and run normally.
Will This Fit My Truck?
This module is a direct replacement for service number 16265035 and is also compatible with part numbers 16263494, 8162634940, 218-11787, and 21811787. It is designed for a wide range of GM vehicles. Please verify your vehicle from the list below:
CHEVROLET 2500 PICKUP 99-00 (Gasoline, ID 16263494 for ’99)
CHEVROLET 3500 PICKUP 99-00 (Gasoline, ID 16263494 for ’99)
SILVERADO 1500 PICKUP 99-00 (4.3L V6)
TAHOE 99-00 (Classic Style for ’00, ID 16263494 for ’99)
SUBURBAN 1500/2500 99 (Gasoline, ID 16263494)
EXPRESS/SAVANA VAN 1500/2500/3500 99-02 (Gasoline, check ID 16263494 for specific years)
ASTRO/SAFARI VAN 99-01 (ID 16263494)
GMC 1500 PICKUP 99 (5.0L, 5.7L, ID 16263494)
GMC 2500/3500 PICKUP 99-00 (Gasoline, ID 16263494 for ’99)
SIERRA 1500 PICKUP 99-00 (4.3L V6)
YUKON 99-00 (ID 16263494 for ’99; Denali for ’00)
ESCALADE 99-00 (ID 16263494 for ’99)
S10/S15/SONOMA 98-00 (4.3L, check build date opt ZN4 for ’98)
BLAZER/JIMMY 98-00 (check build date opt ZN4 for ’98)
BRAVADA 98-00 (check build date opt ZN4 for ’98)
ENVOY 98-00 (check build date opt ZN4 for ’98)
ISUZU HOMBRE 98-00 (4.3L, check build date opt ZN4 for ’98)
This is a partial list. Please ensure your part number matches.
Frequently Asked Questions
Do I need a dealership to program this 1999-2000 Yukon PCM?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN during checkout, and the module will arrive ready to install.
What is the security relearn procedure you mentioned?
It’s a simple process to sync the new PCM with your vehicle’s anti-theft system. It involves cycling the ignition key from ‘ON’ to ‘OFF’ in 10-minute intervals, three times in a row. This can be done in your driveway and requires no special tools.
Will this fix my transmission shifting problems?
If the PCM is the cause of the poor shifting, then yes. The PCM controls the transmission’s electronic solenoids, and a faulty module often leads to harsh or incorrect shifts. This replacement restores proper communication and function.
Where is the VIN located on my vehicle?
You can find your 17-digit Vehicle Identification Number (VIN) on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Is this a guaranteed fix for my check engine light?
This module will correct any diagnostic trouble codes directly caused by a failing PCM, such as internal processor faults. If your check engine light is on due to other issues (like a bad oxygen sensor or catalytic converter), those parts will still need to be addressed separately.