Restore Your Truck’s Brain and Bring It Back to Life
If your trusty 1998-1999 GM truck or van is suddenly running rough, refusing to start, or throwing confusing check engine lights, the problem might be deeper than a simple sensor. The Powertrain Control Module (PCM) is the central computer of your vehicle, managing everything from fuel delivery and spark timing to transmission shifting. When it fails, it can cause a host of frustrating issues that can sideline even the toughest workhorse. This isn’t just a replacement part; it’s a reliable, cost-effective solution to get you back on the road with confidence.
We offer a genuine, salvaged GM PCM that has been meticulously tested and is ready for installation. The best part? We handle the programming for you. Simply provide your vehicle’s VIN after purchase, and our technicians will flash the module with the latest GM factory software specific to your truck. This eliminates the need for an expensive trip to the dealership and ensures your vehicle operates exactly as it was designed to. This is the smart fix for the professional mechanic or the dedicated DIYer looking to solve complex electronic issues without breaking the bank.
From the Diagnostic Bay: Chasing a Ghost in a ’99 Silverado
I remember a customer bringing in his ’99 Silverado 1500 with the 5.7L. He’d thrown a lot of parts at it—new fuel pump, crank sensor, even a distributor—chasing an intermittent no-start and stalling issue. His scanner would lose communication with the PCM randomly. After checking the basics like power and grounds to the module, we knew where to look. The PCM itself was failing internally. A quick swap with one of our pre-programmed units, like this one, had his truck running perfectly in under an hour. He was kicking himself for the time and money spent on other parts, but thrilled to have a reliable truck again. It’s a classic case I’ve seen dozens of times; sometimes the simplest solution is the correct one.
Is Your Truck Showing These Telltale Signs?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need. Look out for these common indicators:
- ✔ Vehicle will not start or starts intermittently.
- ✔ Check Engine Light is on with communication error codes like P0601 or P0606 (Internal Control Module Memory Check Sum Error).
- ✔ Poor or erratic automatic transmission shifting.
- ✔ Drastically reduced fuel economy for no apparent reason.
- ✔ Engine stalling, sputtering, or misfiring.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle with basic tools. Our pre-programming service makes it even easier. Follow these general steps to get your vehicle running again:
- 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.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. These connectors are color-coded, making re-installation simple.
- Remove the Old Module: Unbolt the old 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 re-attach the wiring harness connectors. Ensure they click into place.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Security Relearn (If Necessary): On these models, you will need to perform a security relearn procedure, also known as a CASE learn. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your truck should then start and run normally.
Verified Fitment for Your GM Truck or Van
This PCM is a direct replacement for multiple part numbers and fits a wide range of GM vehicles. Please match your original part number or verify your vehicle is on this list. This module is compatible with units bearing service ID 9355699.
This module is a direct replacement for part numbers: 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, 9366810 and fits models including, but not limited to:
- ✔ 1998-1999 Chevrolet & GMC 1500/2500/3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban & GMC Yukon (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana Vans (1500/2500/3500 Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 S10/S15/Sonoma, Blazer/Jimmy, Bravada, Envoy, Isuzu Hombre (4.3L V6)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential for us to program the PCM with the correct factory software for your specific engine, transmission, and emissions options. This ensures perfect compatibility and performance.
Is this part difficult to install?
No. With our pre-programming service, the physical installation is a simple bolt-off, bolt-on process. The only additional step is a straightforward security relearn procedure that takes about 30 minutes and requires no special tools.
What does a CASE Relearn mean?
CASE stands for Crankshaft Angle Sensor Error. It’s a quick procedure that synchronizes the new PCM with your engine’s crankshaft position sensor. It’s required for accurate ignition timing and misfire detection and is part of the security relearn process.
Is this a new part?
No, this is a high-quality, used OEM part sourced from a salvaged vehicle. Each unit is thoroughly inspected and tested to ensure it functions correctly before being programmed and shipped.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like code P0601) or a related system that the PCM controls, then yes, this will resolve the issue. We always recommend proper diagnosis to confirm the PCM is the point of failure before ordering.