Restore Peak Performance to Your GM Truck or SUV
As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can turn a reliable workhorse into a source of constant frustration. If your 1998-1999 GMC 2500 is suffering from perplexing issues like random stalling, poor fuel mileage, or a persistent Check Engine Light, the root cause is very often this critical component. The PCM is the brain of your vehicle, managing everything from fuel mixture and spark timing to transmission shift points. When it falters, the entire system suffers.
This isn’t just a replacement part; it’s a complete solution. We are offering a high-quality Powertrain Control Module, compatible with part numbers 09366810, 16250279, and 09355699. The most significant benefit we provide is the pre-programming service. Before this module ever leaves our facility, we flash it with the latest official GM software updates, precisely matched to your truck’s Vehicle Identification Number (VIN). This eliminates the need for an expensive trip to the dealership for programming, saving you both time and money. With our programmed 1998-1999 GMC 2500 PCM, you’re getting a component that’s ready to restore your vehicle’s original drivability and efficiency.
A Technician’s Notebook: The Phantom Stall
I once had a ’99 Chevy Suburban come into the bay with an issue that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a stoplight with no warning and no immediate Check Engine Light. He’d already replaced the fuel pump and ignition control module. After checking all the grounds and power feeds to the PCM, everything looked solid. On a hunch, I monitored the 5-volt reference signal from the PCM while tapping on the module’s case. Sure enough, the voltage would dip erratically. The internal circuit board had developed a microscopic crack from years of heat cycles and vibration. A replacement, programmed PCM like this one solved the problem instantly. It’s a classic failure mode for these units, and one that can be very difficult to pinpoint without experience.
Is Your Truck Exhibiting These Symptoms?
A faulty PCM can manifest in numerous ways. If you’re noticing any of the following, it’s a strong indicator that your engine computer may need replacement:
- ✔ Unexplained Check Engine Light illumination
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Read Only Memory Error)
- ✔ Engine cranks but refuses to start
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Noticeable decrease in fuel economy
- ✔ Intermittent stalling or rough idling
- ✔ Failure to pass an emissions inspection
Your Straightforward Installation Guide
Installing your new 1998-1999 GMC 2500 PCM is a manageable job for a confident DIYer. Follow these steps carefully for a successful replacement.
- 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 of these GM trucks and SUVs, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect the Harnesses: The module will have several multi-pin electrical connectors. Carefully release the locking tabs and pull the connectors straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Firmly plug the electrical harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Final Steps: In some cases, a security relearn procedure (often called a Passlock relearn) may be necessary. This procedure is simple and typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for specific steps if required.
Verified Compatibility for Your GM Vehicle
This module is a direct-fit replacement for a wide range of General Motors vehicles. Please verify your part number (16250279, 09366810, or 09355699) and vehicle application from the list below:
ESCALADE 99 (LH front engine compartment), ID 16250279
Chevrolet:
ASTRO 98-99 (LH front by battery), ID 16250279
BLAZER S10 98 (RH front engine compartment), w/o build date opt ZN4; ID 16250279 or 16258815
CHEVROLET 1500 PICKUP 98-99 (Gasoline, LH engine compartment), ID 16250279
CHEVROLET 2500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
CHEVROLET 3500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
EXPRESS 1500/2500/3500 VAN 98 (Gasoline), ID 16250279
S10 PICKUP 98 (4.3L), w/o build date opt ZN4; ID 16250279 or 16258815
SUBURBAN 1500/2500 98-99 (Gasoline, LH front engine compartment), ID 16250279
TAHOE 98-99 (Gasoline, LH engine compartment), ID 16250279
GMC:
GMC 1500 PICKUP 98-99 (Gasoline, LH engine compartment), ID 16250279
GMC 2500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
GMC 3500 PICKUP 98-99 (Gasoline, LH front engine compartment), ID 16250279
ENVOY 98 (RH front engine compartment), w/o build date opt ZN4; ID 16250279 or 16258815
JIMMY S15 98 (RH front engine compartment), w/o build date opt ZN4; ID 16250279 or 16258815
SAFARI 98-99 (LH front by battery), ID 16250279
SAVANA 1500/2500/3500 VAN 98 (Gasoline), ID 16250279
SONOMA 98 (4.3L), w/o build date opt ZN4; ID 16250279 or 16258815
YUKON 98-99 (LH engine compartment), ID 16250279
Isuzu:
HOMBRE 98 (4.3L), w/o extended build date opt ZN4; ID 16258815
Oldsmobile:
BRAVADA 98 (4.3L), w/o build date opt ZN4; ID 16250279 or 16258815
Do I need to get this PCM programmed?
Do I need to get this PCM programmed?
No. The main benefit of our service is that this module arrives at your door fully programmed with the latest GM software for your specific vehicle. All we need is your VIN during checkout. This saves you a costly and time-consuming trip to a dealership.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your order until we receive this information, as it is essential for the programming process.
Is this the same as an ECM or engine computer?
Yes. The terms Powertrain Control Module (PCM), Engine Control Module (ECM), and engine computer are often used interchangeably. For these GM vehicles, the PCM controls both engine and transmission functions, making it the central computer.
Will this fix my ‘No Start’ problem?
If your vehicle’s ‘no start’ condition is caused by a failed PCM, then yes, this part will resolve the issue. A bad PCM is a common cause for a ‘crank, no start’ situation, but be sure to have other potential causes, like the fuel system or ignition components, properly diagnosed.
What if my original part number is not 09366810?
This module is a direct replacement for several part numbers, including 16250279 and 09355699. As long as your original module carries one of these numbers and your vehicle is on our compatibility list, this part will work for you.