Restore Peak Performance to Your Chevy Workhorse
If your 1998-1999 Chevrolet 2500 Pickup is suddenly stalling, running rough, or refusing to start, the problem often points directly to the heart of its electronic system: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless GMT400-platform trucks sidelined by a failing PCM. It’s the brain of your vehicle, controlling everything from fuel injection and spark timing to transmission shift points. When it falters, your truck’s reliability disappears.
This isn’t just another part. This is a dependable, OEM-salvaged PCM that we professionally program to your truck’s specific Vehicle Identification Number (VIN). By flashing it with the latest GM software updates, we ensure it communicates flawlessly with your engine, transmission, and security system right out of the box. You get a cost-effective solution that bypasses the expensive and time-consuming trip to a dealership for programming.
From the Diagnostic Bay: The Ghost in the Machine
I remember a ’99 Suburban that came into my shop with a maddeningly intermittent no-start condition. The owner had already replaced the battery, alternator, and starter. It would run fine for days, then suddenly refuse to crank. After hooking up my scanner, I saw no communication with the PCM. A classic sign. Wiggling the PCM connectors sometimes brought it back to life, indicating an internal board failure. We installed a VIN-programmed PCM just like this one, performed the quick security relearn, and the truck fired up instantly. The “ghost” was gone, and the customer had his reliable family hauler back. These failures are common, but the fix is straightforward with the right part.
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 the likely solution:
- ✔ Check Engine Light is on with codes like P0601, P0602, P0605, or P0606 (Internal Control Module errors).
- ✔ The engine cranks but won’t start.
- ✔ Unexplained stalling or rough idling.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ The security or anti-theft light stays on, preventing startup.
- ✔ No communication with the PCM when using a diagnostic scan tool.
Your Straightforward PCM Installation Guide
Replacing the PCM on these trucks is a job most DIYers can handle in under an hour. This pre-programmed module makes it even simpler. Here’s a general guide:
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1998-1999 Chevy/GMC trucks, the PCM is located in the engine compartment on the driver’s side, near the fender or firewall.
- Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old PCM. There are typically multiple color-coded connectors. Take your time to avoid damaging the clips.
- 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-fasten the bolts.
- Reconnect Everything: Plug the harness connectors into the new PCM, ensuring they click firmly into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, a simple 10-minute security relearn procedure is required. Turn the key to the ‘ON’ position (don’t start) for 10 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle three times. On the fourth try, the vehicle should start.
Verified Compatibility for Your GM Vehicle
This PCM, identified by service ID 9355699, is a direct replacement for a wide range of GM trucks and vans. It is compatible with part numbers 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. It fits the following gasoline-engine models:
- ✔ 1998-1999 Chevrolet/GMC 1500, 2500, & 3500 Pickups
- ✔ 1998-1999 Chevrolet Suburban & Tahoe / GMC Yukon
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana Vans (1500/2500/3500)
- ✔ 1998 Chevrolet Astro & GMC Safari Vans
- ✔ 1998 S10/S15/Sonoma, Blazer/Jimmy, Oldsmobile Bravada, Isuzu Hombre (4.3L V6)
- ✔ 1998 Oldsmobile Bravada & GMC Envoy
This is the reliable, no-hassle solution to get your 1998-1999 Chevrolet 2500 PCM issues resolved and your truck running like it should.
Frequently Asked Questions
What do I need to do after I purchase?
After your purchase, simply reply to your order confirmation email with your vehicle’s 17-digit VIN. We cannot program and ship the module without it. This ensures the PCM is a perfect match for your truck’s factory specifications.
Is any other programming required after installation?
In most cases, no. Our VIN programming handles the engine and transmission software. You may need to perform a simple security relearn procedure that takes about 30 minutes and requires only your ignition key. On some models, a Crankshaft Variation Relearn (CASE) may be needed with a scan tool to clear a P1336 code, but the truck will run and drive without it.
Is this a new part?
No, this is a high-quality, tested component sourced from a salvaged vehicle. We inspect and verify each unit for full functionality before programming and shipping. This provides an OEM-grade part at a significant cost savings over a new dealer unit.
Why is my part number different from 16258815?
GM uses many different part numbers for the same physical computer. This module, often identified by the service ID 9355699, is the correct replacement for all part numbers listed in the description, including 16258815, 09355699, 16266645, and others.
Will this fix my transmission shifting problems?
If the shifting problems are caused by faulty electronic signals from the PCM, then yes. The PCM controls the transmission’s electronic solenoids. A failing module can cause harsh shifts, delayed engagement, or incorrect gear selection. This part restores that critical communication.