Restore Peak Performance to Your GMT400 Truck
As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can turn a reliable workhorse like your 1998-1999 Chevrolet 2500 Pickup into a source of constant frustration. If you’re dealing with perplexing engine issues, erratic transmission behavior, or a persistent check engine light, you’ve come to the right place. This isn’t just a replacement part; it’s a direct, reliable solution to get your truck running the way it should.
This is a quality, tested, used OEM PCM, part number 9366810, sourced from a salvaged vehicle. The real value, however, lies in our professional programming service. Before we ship it, we flash the module with the latest official GM software updates, precisely matched to your truck’s Vehicle Identification Number (VIN). This critical step ensures seamless communication between your engine, transmission, and other onboard systems, eliminating the need for an expensive trip to the dealership for programming. It arrives at your door ready to install.
Case Study: The Ghost in the Machine
I remember a customer with a ’99 Suburban who was ready to sell it for scrap. The truck had an intermittent no-start condition, would randomly stall at stoplights, and the transmission would sometimes refuse to shift out of first gear. He had replaced the battery, alternator, and even the fuel pump, but the problems persisted. After hooking up my scan tool, I noticed some odd voltage readings and a generic internal controller error (P0601). Experience pointed me straight to the PCM. Once we installed a VIN-programmed module like this one, all the ‘ghosts’ vanished. The truck ran smoother than it had in years. That’s the difference the right, correctly programmed part makes.
Is Your Truck Showing These PCM Failure Signs?
A failing PCM can cause a wide range of symptoms that often get misdiagnosed. If you’re experiencing any of the following, your engine computer is a likely culprit:
- ✔ Check Engine Light is on with codes like P0601, P0605, or other communication errors.
- ✔ Engine cranks but refuses to start.
- ✔ Rough or unstable idling.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent stalling for no apparent reason.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Installing your replacement 1998-1999 Chevrolet 2500 PCM is a manageable job for a confident DIYer. Taking your time and following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these GM trucks and vans, you’ll find the PCM in the engine bay, typically on the driver’s side inner fender.
- Disconnect the Wiring: Carefully unplug the wiring harness connectors from the old PCM. These connectors have locking tabs that may need to be gently pried up or squeezed to release. Inspect the connectors for any corrosion or damaged pins.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in by a few bolts.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses into the new PCM until they click into place. Reconnect the negative battery terminal.
- Security Relearn Procedure: In many cases, you will need to perform a security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the vehicle’s security system to recognize the new PCM. Check your specific model’s procedure for exact details.
Verified Fitment For These GM Vehicles
This module is a direct replacement for service number 9355699 and several other part numbers. Please verify your part number or use the compatibility list below. This part is guaranteed to fit the following vehicles:
CHEVROLET/GMC SUBURBAN 1500/2500 (1998-1999, Gasoline)
CHEVROLET TAHOE / GMC YUKON (1998-1999, Gasoline)
CADILLAC ESCALADE (1999)
CHEVROLET EXPRESS / GMC SAVANA VANS 1500/2500/3500 (1998-1999, Gasoline)
CHEVROLET ASTRO / GMC SAFARI (1998)
OLDSMOBILE BRAVADA (1998)
GMC ENVOY (1998)
CHEVROLET S10 / GMC SONOMA / ISUZU HOMBRE (1998, 4.3L V6)
CHEVROLET BLAZER / GMC JIMMY (1998)
Note: This is a comprehensive list. Always match your service ID (e.g., 9355699) found on your original module’s sticker for 100% confirmation.
By purchasing this 1998-1999 Chevrolet 2500 PCM, you’re getting a cost-effective and reliable fix that has been professionally prepared for your specific vehicle. Stop chasing electronic gremlins and get your truck back to work.
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after I install it?
Because this PCM is pre-programmed to your VIN, it’s virtually plug-and-play. However, you will likely need to perform a simple security relearn procedure, which takes about 30 minutes and doesn’t require any special tools.
How do I provide my VIN?
After you complete your purchase, simply send us a message with your 17-digit VIN. We cannot program and ship the module without it. Please double-check it for accuracy.
Is this a new part?
No, this is a high-quality, tested used OEM part that has been sourced from a salvaged vehicle. This provides OEM reliability at a fraction of the cost of a new unit.
What if my original part number is different?
This module, identified by part number 9366810, also replaces several other common part numbers like 09355699 and 16266645. As long as your vehicle is on our fitment list and uses one of the compatible part numbers, this module will work once programmed.
What is the benefit of getting it programmed before shipping?
Programming a PCM requires expensive, specialized equipment. By having us program it to your VIN, you save hundreds of dollars and the hassle of a dealership visit. It arrives ready for installation and the security relearn process.