Restore Your Truck’s Brainpower and Get Back on the Road
If your trusty 1998-1999 Chevy 2500 is suffering from perplexing issues like a no-start condition, erratic shifting, or a persistent Check Engine Light, the problem often points to a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can cause a cascade of problems that are frustrating to diagnose. This isn’t just a replacement part; it’s a direct solution, a tested, used PCM that arrives at your door programmed with the latest GM software specific to your truck’s Vehicle Identification Number (VIN).
From the Diagnostic Bay: The Case of the Confusing Codes
I remember a customer bringing in his ’99 Suburban—same platform as your truck—with a list of complaints: poor fuel economy, a transmission that shifted hard from first to second, and a check engine light that his local parts store scanned as a random sensor fault. They had him replace two sensors with no change. In my bay, my pro-level scanner pulled a P0601 (Internal Control Module Memory Check Sum Error). This code is a definitive sign the PCM’s internal processor is failing. No amount of sensor swapping will fix it. We installed a VIN-programmed PCM just like this one, and it immediately resolved all the issues. It’s a reminder that getting to the root cause saves time and money, and for these GMT400 trucks, a failing PCM is a very common root cause.
Is Your Truck Showing These Telltale Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution you need. Over my 20 years in the shop, these are the most frequent symptoms I’ve traced back to a bad engine computer on these GM trucks.
- ✔ Complete no-start or intermittent starting problems.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A persistent Check Engine Light with codes like P0601, P0604, or P0606.
- ✔ Poor engine performance, hesitation, or stalling.
- ✔ Communication loss codes (U-codes) with other modules.
- ✔ Decreased fuel economy for no apparent reason.
A Straightforward Guide to Installation
Replacing the 1998-1999 Chevrolet 2500 PCM is a job most DIYers can handle with basic tools. Because we program it for you, there are no special computer tools needed for the installation itself. Just follow these steps carefully.
- Safety First: Always disconnect the negative terminal from your truck’s battery and secure it away from the post to prevent any accidental reconnection.
- 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.
- Disconnect the Wiring: Carefully unclip and remove the electrical connectors from the old PCM. These connectors have locking tabs; be gentle to avoid breaking them. Note their color and position.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few bolts.
- Install the New PCM: Mount your replacement PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the correct ports on your new PCM. The connectors are keyed to only fit one way. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, you will need to perform a simple 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 anti-theft system to recognize the new PCM. Your truck will not start until this is completed.
Verified Vehicle Compatibility
This module, identified by service number 9355699, is a direct fit for a wide range of GM vehicles. Please confirm your vehicle is on this list. This unit is compatible with part numbers 09355699, 16266645, 16250279, 16258815, and 9366810.
GMC 1500/2500/3500 PICKUP (1998-1999, Gasoline)
CHEVROLET SUBURBAN 1500/2500 (1998-1999, Gasoline)
CHEVROLET TAHOE (1998-1999, Gasoline)
GMC YUKON (1998-1999)
CADILLAC ESCALADE (1999)
CHEVROLET EXPRESS 1500/2500/3500 VAN (1998-1999, Gasoline)
GMC SAVANA 1500/2500/3500 VAN (1998-1999, Gasoline)
ASTRO / SAFARI VAN (1998)
S10/S15/SONOMA (1998, 4.3L)
BLAZER S10/JIMMY S15 (1998)
OLDSMOBILE BRAVADA (1998)
GMC ENVOY (1998)
ISUZU HOMBRE (1998, 4.3L)
Frequently Asked Questions
What do you need from me to program the PCM?
After you complete your purchase, simply send us your 17-digit Vehicle Identification Number (VIN). We use this to load the correct, GM-certified software for your specific vehicle configuration, ensuring perfect compatibility.
Do I need to have a dealer perform any additional steps?
No. This PCM comes fully programmed. The only step you may need to perform is a simple security relearn procedure, which does not require any special tools and can be done in your driveway. Instructions are widely available online or we can provide them.
Is this a new part?
No, this is a thoroughly tested, used OEM part sourced from a salvaged vehicle. This provides OEM reliability and functionality at a fraction of the cost of a new unit from a dealership.
My part number is slightly different. Will this work?
Yes, as long as your vehicle is on the compatibility list. This module, ID 9355699, directly replaces several part numbers including 16266645, 16250279, and 09366810. We program it to function identically to the one originally in your vehicle.
How do I find my vehicle’s VIN?
Your VIN can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.