Restore Peak Performance to Your GM Truck
If your late-90s Chevy or GMC truck is suddenly stalling, shifting erratically, or refusing to start, the problem often points directly to a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen these symptoms countless times. The PCM is the brain of your vehicle’s engine and transmission, and when it falters, it can cause a host of frustrating and hard-to-diagnose issues. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded. This genuine used OEM module is the straightforward, cost-effective solution to get your workhorse back on the road.
We take the guesswork and hassle out of the repair. This isn’t just a part in a box; it’s a complete solution. Before we ship it, we program the module with the latest GM software updates using the specific Vehicle Identification Number (VIN) from your truck. This ensures that when it arrives, it’s ready for a simple, plug-and-play installation. You get to skip the expensive trip to the dealership for programming, saving you both time and hundreds of dollars in labor and towing fees. This is the ideal fix for the savvy DIYer or professional mechanic looking for a reliable repair.
From the Diagnostic Bay: The Intermittent No-Start Nightmare
I remember a 1999 GMC Yukon that came into my shop on a tow truck. The owner was at his wit’s end. The truck would run perfectly for a week, then refuse to start for a day. He had already replaced the battery, alternator, and starter. The check engine light was off, and there were no stored codes. After checking fuel pressure and spark, which were both fine when it decided to run, I focused on the 1998-1999 Chevrolet 1500 PCM, a common component across these platforms. On these older GMT400s, heat soak and age can cause microscopic cracks in the PCM’s circuit board, leading to these maddening intermittent failures. We swapped in a VIN-programmed module, and the problem vanished instantly. The owner was thrilled to have a reliable truck again without spending a fortune chasing ghosts.
Common Signs of a Failing PCM
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ Your vehicle will not start or is very difficult to start.
- ✔ The engine stalls, stumbles, or misfires for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ The automatic transmission is shifting harshly, late, or not at all.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- ✔ Locate the PCM: On most 1998-1999 GM trucks and SUVs, the PCM is located in the engine bay on the driver’s side, near the fender or firewall.
- ✔ Disconnect the Harnesses: Carefully unclip and disconnect the electrical wiring harnesses from the old PCM. These connectors have locking tabs that may need to be gently pried up.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you may need it for the new installation.
- ✔ Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely reconnect the wiring harnesses. You should hear a click as they lock into place.
- ✔ Reconnect the Battery: Re-attach the negative battery terminal.
- ✔ Perform Security Relearn: For many of these vehicles, 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’ for 10 seconds, and repeating this cycle three times. This allows the vehicle’s anti-theft system to recognize the new 1998-1999 Chevrolet 1500 PCM.
Verified Vehicle Compatibility
This module, identified by service number 16258815 or Hollander ID 590-05150 (often marked with ID 09355699), is a direct replacement for a wide range of GM trucks, vans, and SUVs. Please verify your part number or consult the list below to ensure proper fitment. This unit replaces part numbers: 09355699, 16266645, 16250279, 16258815, 09366810.
Fits models such as:
- ✔ 1998-1999 Chevrolet & GMC C/K 1500, 2500, 3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- ✔ 1998-1999 Chevrolet & GMC Suburban (Gasoline)
- ✔ 1999 Cadillac Escalade
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500, 2500, 3500 Vans (Gasoline)
- ✔ 1998 Chevrolet Astro & GMC Safari
- ✔ 1998 Chevrolet S10, GMC Sonoma, Isuzu Hombre (4.3L V6)
- ✔ 1998 Chevrolet Blazer, GMC Jimmy, Oldsmobile Bravada
This is a reliable and tested 1998-1999 Chevrolet 1500 PCM that offers a dependable fix to restore your vehicle’s proper function.
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN during checkout, and the module will arrive ready to install with the latest GM software updates for your specific vehicle.
What is a security relearn procedure?
This is a simple, tool-free process required by GM’s Passlock/VATS anti-theft system to sync with the new PCM. It typically takes about 30 minutes and involves cycling the ignition key. We include instructions to guide you through it.
Is this a new part?
This is a genuine OEM part that has been sourced from a salvaged vehicle. Each unit is thoroughly inspected and tested to ensure it is fully functional before being programmed and shipped.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine functions and transmission shift points. If the PCM is faulty, it can cause poor shifting, and replacing it with a correctly programmed unit will often resolve these issues.
How do I find my original part number?
Your original part number is printed on a sticker on the PCM itself. You can cross-reference it with the numbers listed in our description, such as 16258815 or 09355699, to confirm compatibility.