Restore Your GM Truck’s Brain with a Plug-and-Play Solution
Is your 1998-1999 Tahoe, Suburban, or Yukon acting up? If you’re dealing with a persistent check engine light, poor engine performance, or frustrating no-start conditions, the problem often points to a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty PCM can cripple an otherwise solid truck. This isn’t just a part; it’s the central computer managing your engine’s fuel, spark, and transmission. When it fails, your vehicle’s reliability is gone.
We offer a straightforward, dependable fix: a genuine, used OEM PCM that we program specifically to your vehicle’s VIN before it ships. This means no expensive trips to the dealership for programming. You get a part that’s loaded with the latest GM software updates, ready to install right out of the box. It’s the most efficient way to get your truck back to running the way it should.
From the Diagnostic Bay: The ’99 Suburban That Wouldn’t Communicate
A customer brought in a ’99 Suburban 1500. It would crank but not start, and the fuel pump wasn’t priming. The check engine light was on, but my high-end scan tool couldn’t communicate with the PCM—a classic red flag. After checking the basics (fuses, grounds, and power at the PCM connector), it was clear the module itself was the culprit. These older PCMs, especially the ones with part ID 9355699, are known for internal circuit board failures over time. We installed one of our pre-programmed units, performed the quick security relearn, and the truck fired right up. The customer saved hundreds compared to the dealer and was back on the road the same day. This is the exact solution we provide to you.
Is Your Truck or Van Showing These Symptoms?
A failing PCM can cause a wide range of issues. If you’re experiencing any of the following, this module is a likely solution:
- ✔ Check Engine Light is on with communication error codes or internal module failure codes (e.g., P0601, P0605).
- ✔ Vehicle cranks but refuses to start.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Engine stalling, stuttering, or misfiring for no apparent reason.
- ✔ Failure to pass an emissions test due to PCM-related faults.
A Straightforward Guide to Installation
Installing your replacement 1998-1999 Tahoe PCM is a job most DIYers can handle in under an hour. While your specific vehicle may have slight variations, this is the general process.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or firewall.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. There are usually multiple color-coded connectors with locking tabs.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new module.
- Install the New Module: Mount your pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the correct slots on your new PCM. The connectors are keyed to only fit one way. Reconnect the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure (often called a Passlock or VATS relearn) to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to ‘ON’ for 10-15 minutes. We include instructions for this simple process.
Verified Vehicle Compatibility
This engine computer, identified by service number 16266645 or ID 9355699, is a direct replacement for a wide range of GM trucks and vans from the late 1990s. While it’s a perfect fit for the 1998-1999 Tahoe PCM requirement, it also fits many other models. This includes the GMC Yukon, Chevrolet and GMC Suburban, C/K 1500/2500/3500 pickups, Express and Savana vans, as well as the S-10, Blazer, Jimmy, and Bravada platforms. Please use the comprehensive fitment list on this page to confirm this part is the correct one for your specific year, model, and engine. Matching the part number or ID is the best way to guarantee compatibility.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, correct GM factory software for your truck’s specific engine, transmission, and options. This ensures a true plug-and-play installation and proper vehicle operation.
What is the ‘Security Relearn’ procedure?
The security relearn is a simple process that syncs the new PCM to your vehicle’s anti-theft system. It typically involves a sequence of key turns and waiting periods. We provide easy-to-follow instructions with your order. No special tools are required.
Is this a new part?
No, this is a high-quality, tested, and reliable used OEM part sourced from a salvaged vehicle. We find these genuine GM units to be more dependable than many aftermarket alternatives. It is fully inspected and then programmed with fresh software.
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 a failing PCM, this part will resolve them. If the problem is mechanical within the transmission, it will not.
What do I do after I place my order?
After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your PCM until we receive this information. The sooner we get it, the faster you get your part!