If your reliable Chevy truck is suddenly giving you headaches—stalling, running rough, or refusing to start—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 engine computer can bring a powerful workhorse to a dead stop. This isn’t just an inconvenience; it’s lost time and money. This listing is for a dependable, used OEM PCM that gets you back on the road without the dealership hassle or expense.
This isn’t just a part in a box. It’s a complete solution. Before we ship it, we program this module specifically to your truck’s Vehicle Identification Number (VIN). This critical step ensures that all the factory parameters for your engine, transmission, and emissions systems are correctly loaded. It arrives with the latest GM software updates, often correcting issues the original programming had. When you install this 1998-1999 Chevrolet 3500 PCM, it’s ready to work, communicating seamlessly with your vehicle’s other modules.
From the Diagnostic Bay: The Case of the Heat-Soaked Stall
I remember a customer with a ’99 Suburban who was at his wit’s end. The truck ran perfectly when cold, but after 20-30 minutes of driving, it would sputter and die at stoplights. No check engine light, no obvious cause. After checking fuel pressure and ignition components, we focused on the PCM. On these older GM trucks, the PCM is mounted in the engine bay where it’s exposed to intense heat. Over years, the internal circuits can develop micro-fractures that only separate and cause a failure when they get hot. We swapped in a tested, pre-programmed PCM, and the problem vanished instantly. That’s a classic failure mode for these units, and it’s a problem our tested modules solve.
Is Your GM Truck Showing These Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is a likely solution:
- ✔ Unexplained Check Engine Light with codes like P0601 (Internal Memory Fault) or P0606 (PCM Processor Fault)
- ✔ Engine stalls intermittently, especially after warming up
- ✔ Rough or erratic idle
- ✔ Complete no-start condition where the engine cranks but won’t fire
- ✔ Poor fuel economy and noticeable loss of power
- ✔ Harsh or incorrect automatic transmission shifting
- ✔ Communication errors with a scan tool
A Straightforward Guide to Installation
Replacing the 1998-1999 Chevrolet 3500 PCM is a job most DIYers can handle in under an hour with basic tools. This module is typically located in the engine compartment on the driver’s side.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: Find the existing module in the engine bay. It will have several large wiring harness connectors attached.
- Disconnect the Harnesses: Carefully unclip and remove all electrical connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your replacement PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the new PCM, ensuring they click firmly into place. Reconnect the negative battery terminal.
- Perform Security Relearn: On many GM vehicles of this era, you will need to perform a simple security relearn procedure (often called Passlock relearn) to sync the new PCM with your key. This procedure typically takes about 30 minutes and requires no special tools. Search online for the specific steps for your model.
Verified Vehicle Compatibility
This PCM, identified by service number 09366810 and interchange ID 9355699, is a direct replacement for a wide range of General Motors trucks and vans. While this listing is for a 1998-1999 Chevrolet 3500 PCM, please verify your part number or check the comprehensive list below to ensure a perfect match for your vehicle. Providing your VIN is the final step to guarantee compatibility.
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after installing it?
Because this PCM comes pre-programmed to your VIN, the main step after physical installation is the security relearn procedure (Passlock). This allows the vehicle’s anti-theft system to recognize the new computer. It’s a simple key-on/key-off sequence that takes around 30 minutes.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. We inspect and verify the functionality of each unit before programming and shipping it to you, offering a reliable and cost-effective alternative to a new module.
How do I provide my VIN?
After completing your purchase, simply send us a message with your vehicle’s 17-digit VIN. We cannot program and ship the module without this information.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like DTC P0601), then yes, this will resolve the issue. However, if the light is on due to a faulty sensor or other component, you will still need to repair that underlying problem.
What if my part number is slightly different?
This module replaces several part numbers, including 09355699, 16266645, 16250279, and more. As long as your original part number is on our cross-reference list, this module will function correctly once programmed to your VIN.