Restore Your GM Truck’s Brain and Get Back on the Road with Confidence
As a technician with over two decades of experience under the hood, I’ve seen firsthand the frustration a failing Powertrain Control Module (PCM) can cause on these otherwise bulletproof 1998-1999 GM trucks and SUVs. You’re dealing with a vehicle that won’t start reliably, guzzles gas, or has a Check Engine Light that just won’t go away. This isn’t just an inconvenience; it’s a core reliability issue. The PCM is the central computer for your engine and transmission, and when it fails, the symptoms can be maddeningly inconsistent. That’s why we offer a straightforward, reliable solution: a high-quality replacement PCM, part number 16250279, programmed specifically for your vehicle.
Forget the expensive trip to the dealership and the hassle of trying to find a shop that can program an older module. We handle the critical programming for you. Simply provide your vehicle’s VIN at checkout, and our experts will flash the module with the latest GM-approved software updates. This ensures it communicates perfectly with your Tahoe’s engine, transmission, and security system right out of the box. This is the definitive fix for a wide range of performance problems, restoring your truck’s original power, efficiency, and dependability.
Case Study: The Ghost in the Machine
I remember a 1999 Suburban that came into my shop with a classic intermittent no-start. The owner had replaced the battery, alternator, and starter, but the truck would still randomly refuse to crank. There were no consistent trouble codes. After hours of tracing wires, we hooked up a scope to the PCM’s power and ground circuits. We found that during crank attempts, the PCM’s internal voltage would drop erratically, causing it to shut down the starter relay. It was a failing internal component that only acted up under load. We installed a VIN-programmed PCM, and the problem was solved instantly. This is a perfect example of how a faulty 1998-1999 Tahoe PCM can create phantom issues that are nearly impossible to diagnose without replacing the unit.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, a faulty module is a likely culprit:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or other communication faults.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine cranks but refuses to start (intermittent or constant).
- ✔ Significant drop in fuel economy for no apparent reason.
- ✔ Stalling, stumbling, or rough idling.
- ✔ Failure to pass an emissions/smog test.
- ✔ No communication with your scan tool.
A Straightforward Guide to Installation
Replacing the PCM on these GM models is a job most DIYers can handle in their own driveway. Follow these general steps to get your truck running right.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most Tahoes, Suburbans, and pickups, the PCM is located in the engine bay on the driver’s side, near the fender or firewall. It’s a silver metal box with several large wiring harness connectors.
- Disconnect the Harnesses: Carefully unclip and remove all electrical connectors from the old PCM. These connectors have locking tabs that may need to be gently pried up.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new unit.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten it.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click firmly into place. Reconnect the negative battery terminal.
- Perform Crankshaft Variation Relearn (CASE Relearn): While the truck will start and run, a CASE relearn using a capable scan tool is recommended to synchronize the new PCM with the crankshaft position sensor for optimal performance and to prevent a P1336 trouble code. Many local shops can perform this service for a small fee if you don’t have the tool.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. Please match your original part number or verify fitment with the list below. This unit is confirmed to fit the following vehicles:
TAHOE 98-99 Gasoline (LH front engine compartment), ID 16250279
YUKON 98-99 (LH engine compartment), ID 16250279
CHEVROLET 1500/2500/3500 PICKUP 98-99 Gasoline, ID 16250279
GMC 1500/2500/3500 PICKUP 98-99 Gasoline, ID 16250279
SUBURBAN 1500/2500 98-99 Gasoline, ID 16250279
ASTRO 98-99 (LH front by battery), ID 16250279
SAFARI (GMC) 98-99 (LH front by battery), ID 16250279
EXPRESS 1500/2500/3500 VAN 98 Gasoline, ID 16250279
SAVANA 1500/2500/3500 VAN 98 Gasoline, ID 16250279
BLAZER S10/JIMMY S15 98 (RH front engine comp), w/o opt ZN4; ID 16250279 or 16258815
S10/S15/SONOMA 98 4.3L, w/o opt ZN4; ID 16250279 or 16258815
BRAVADA 98 4.3L, w/o opt ZN4; ID 16250279 or 16258815
ENVOY 98 (RH front engine comp), w/o opt ZN4; ID 16250279 or 16258815
ISUZU HOMBRE 98 4.3L, w/o opt ZN4; ID 16250279 or 16258815
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after installing this PCM?
Because this module comes programmed to your VIN, your vehicle’s security system (Passlock/VATS) should not require a relearn. The truck will start and drive. However, a Crankshaft Variation Relearn (CASE relearn) is highly recommended with a compatible scan tool to ensure the engine runs at peak efficiency and to prevent certain trouble codes.
How do I provide my VIN number?
After you complete your purchase, you will receive instructions on how to send us your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it.
Is this a brand new part?
This is a high-quality, inspected, and tested existing OEM unit that has been professionally prepared and programmed with the latest software for your vehicle. It is guaranteed to restore your vehicle’s functionality.
What if my original part number is not 16250279?
This module is also a direct replacement for part numbers 09366810 and 09355699. Please check the fitment list or contact us with your VIN if you are unsure about compatibility.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both the engine and the transmission. If your shifting issues are caused by faulty electronic signals from the PCM, this replacement module will resolve them. It cannot fix internal mechanical failures in the transmission.