Restore Your Truck’s Brain and Get Back on the Road
Is your 1998-1999 GMC Suburban 2500 or other GM truck acting up? Dealing with a frustrating no-start condition, erratic shifting, a persistent Check Engine Light, or poor fuel economy can bring any project or workday to a grinding halt. As a technician with over two decades of experience under the hood, I’ve seen countless drivers spend a fortune chasing symptoms when the real culprit is a failing Powertrain Control Module (PCM). The PCM is the central computer of your vehicle, managing everything from fuel injection and spark timing to transmission shift points. When it fails, the symptoms can be confusing and widespread.
This isn’t just a used part pulled from a yard. This is a complete, cost-effective solution. We take a reliable, tested OEM computer and flash it with the latest official GM software updates specific to your vehicle’s VIN. This means you’re getting a component that not only fixes the problem but also includes any drivability and efficiency improvements GM released after your truck left the factory. Forget expensive dealership programming fees and long waits. We handle the critical programming for you, so you receive a part that’s ready for installation right out of the box.
From the Diagnostic Bay: The ‘Bad Fuel Pump’ That Wasn’t
I remember a 1999 Tahoe that came into my shop on a tow truck. The owner had already replaced the fuel pump himself, convinced it was the cause of his intermittent no-start and stalling issues. When he turned the key, you could hear the new pump prime, but the engine would only crank. After checking for fuel pressure and spark—which were both erratic—I connected my scan tool. There were no fuel-related codes, but a dreaded P0601 (Internal Control Module Memory Check Sum Error) was stored. The PCM’s internal processor was failing, causing it to send corrupted signals to the fuel and ignition systems. We installed a VIN-programmed PCM just like this one, performed the quick security relearn, and the Tahoe fired up on the first try and ran smoother than it had in years. It’s a classic case where chasing the symptom costs more time and money than correctly diagnosing the root cause: the PCM.
Is Your GM Truck Showing These Telltale Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, a faulty computer could be the reason. This is especially true if you see diagnostic trouble codes (DTCs) like P0601, P0602, P0604, or P0605.
- ✔ Check Engine Light is on with no clear cause
- ✔ Vehicle will crank but refuses to start
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Unexplained drop in fuel mileage
- ✔ Engine stalling, sputtering, or misfiring
- ✔ Failure to pass an emissions test
- ✔ Communication errors with a scan tool
A Straightforward Guide to Installation
Replacing the PCM in these GM trucks is a job most DIYers can handle in under an hour with basic hand tools. Our pre-programming service eliminates the most difficult step. Follow this general guide for a smooth installation.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery. It’s a silver metal box with multiple large electrical connectors.
- Disconnect the Connectors: Carefully unlatch and remove all electrical harness connectors from the old PCM. These connectors are often color-coded to prevent mix-ups.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Plug the electrical connectors firmly into the new module. Ensure they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): Some vehicles with Passlock/VATS security systems may require a simple key-cycle relearn procedure. This typically involves turning the key to ‘ON’ for 10-15 minutes, then ‘OFF’, and repeating two more times. Your vehicle’s service manual will have the exact steps.
Verified Compatibility for Your GM Vehicle
This module, identified by service number 9355699, is a direct replacement for a wide range of GM vehicles. It is also a compatible replacement for part numbers 16266645, 16250279, 16258815, 09366810. Please verify your vehicle is on this list and that your original module carries one of these numbers for guaranteed compatibility.
- ✔ Cadillac Escalade: 1999
- ✔ Chevrolet/GMC Pickups (1500, 2500, 3500): 1998-1999 (Gasoline)
- ✔ Chevrolet/GMC Suburban (1500, 2500): 1998-1999 (Gasoline)
- ✔ Chevrolet Tahoe / GMC Yukon: 1998-1999 (Gasoline)
- ✔ Chevrolet Express / GMC Savana Vans (1500, 2500, 3500): 1998-1999 (Gasoline)
- ✔ Chevrolet Astro / GMC Safari: 1998
- ✔ Chevrolet S10 / GMC Sonoma: 1998 (4.3L)
- ✔ Chevrolet Blazer / GMC Jimmy: 1998 (4.3L)
- ✔ Oldsmobile Bravada: 1998 (4.3L)
- ✔ GMC Envoy: 1998 (4.3L)
- ✔ Isuzu Hombre: 1998 (4.3L)