Restore Peak Performance to Your Workhorse Truck
Is your 1998-1999 Chevrolet 3500 Pickup running rough, stalling, or showing a persistent Check Engine Light? A failing Powertrain Control Module (PCM) is often the culprit behind these frustrating and performance-robbing issues. As the central computer of your truck, the PCM governs everything from fuel mixture and ignition timing to transmission shift points. When it falters, your truck’s reliability and efficiency suffer. This replacement PCM is the definitive solution, arriving at your door fully programmed with the latest GM software updates, specifically matched to your truck’s VIN.
From the Diagnostic Bay: The Case of the Confused 3500
I remember a ’99 Chevy 3500 dually that came into my shop a while back. The owner used it for his landscaping business and was losing money every day it was down. The complaint was intermittent stalling at idle and harsh, unpredictable shifting from the 4L80E transmission. He’d already replaced the throttle position sensor and cleaned the MAF sensor with no luck. The only code stored was a P0601 (Internal Control Module Memory Check Sum Error). This code is a direct indictment of the PCM itself. We confirmed power and grounds to the module were solid, which pointed to internal failure. Instead of a costly dealer visit, we installed a VIN-programmed module just like this one. The truck fired right up, the shifting smoothed out instantly, and the P0601 code was gone for good. It’s a classic failure on these GMT400 trucks, and a properly programmed module is the only correct fix.
Is Your Truck Showing These Telltale Signs?
- ✔ Unexplained Check Engine Light illumination
- ✔ Stored diagnostic trouble codes (DTCs) like P0601, P0604, or P0606
- ✔ Poor or erratic engine performance, including stalling or rough idling
- ✔ Harsh or incorrect automatic transmission shifting
- ✔ Decreased fuel economy
- ✔ Failure to pass state emissions testing
- ✔ Complete no-start condition where the engine cranks but won’t fire
Replacing your faulty computer with this pre-flashed 1998-1999 Chevrolet 3500 PCM is the most effective way to resolve these problems and restore the dependable operation you rely on.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your truck’s battery and secure it away from the post to prevent accidental contact.
- ✔ Locate the Module: On your Chevrolet 3500, the PCM is typically found in the engine compartment on the driver’s side, near the firewall or inner fender.
- ✔ Disconnect Wiring: Carefully unclip and remove the electrical connectors from the old PCM. These connectors have locking tabs that need to be released before pulling.
- ✔ Remove the Old PCM: Unbolt the module from its mounting bracket. Keep the hardware as you will need it for the new module.
- ✔ Install the New PCM: Mount your new, VIN-programmed PCM onto the bracket and secure it with the original hardware.
- ✔ Reconnect Everything: Firmly plug the electrical connectors into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Check: Turn the key to the ‘On’ position for 10-15 seconds before starting the engine. This allows the system to recognize the new module. Start your truck and enjoy the restored performance! No dealer visit is required.
Verified Compatibility for Your GM Vehicle
This module, service number 09355699, is a direct replacement for part numbers 16250279 and 09366810. It is guaranteed to fit the following vehicles with gasoline engines (please verify your part number or contact us with your VIN):
- Chevrolet 3500 Pickup (1998-1999)
- Chevrolet 1500/2500 Pickup (1998-1999)
- Chevrolet Astro Van (1998-1999)
- Chevrolet Blazer S10 (1998)
- Chevrolet Express 1500/2500/3500 Van (1998)
- Chevrolet S10 Pickup (1998)
- Chevrolet Suburban 1500/2500 (1998-1999)
- Chevrolet Tahoe (1998-1999)
- Cadillac Escalade (1999)
- GMC 1500/2500/3500 Pickup (1998-1999)
- GMC Envoy (1998)
- GMC Jimmy S15 (1998)
- GMC Safari Van (1998-1999)
- GMC Savana 1500/2500/3500 Van (1998)
- GMC Sonoma (1998)
- GMC Yukon (1998-1999)
- Isuzu Hombre (1998)
- Oldsmobile Bravada (1998)
Frequently Asked Questions
Do I need to program this module after I receive it?
No. This is the biggest benefit we offer. We program the module to your vehicle’s specific VIN before shipping it to you. It arrives ready for a simple, plug-and-play installation.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). You can typically add this in the notes section at checkout or reply to your order confirmation email. We cannot ship your part until we receive the VIN.
Will this fix my specific problem?
This module corrects issues directly caused by a failing PCM, such as internal processor faults (P0601), communication errors, and erratic engine/transmission behavior. While it solves many common problems, you should ensure your vehicle has been properly diagnosed by a professional mechanic or experienced DIYer.
Where is the PCM located on my 1999 Chevy 3500?
On most 1998-1999 Chevrolet and GMC full-size trucks and SUVs, the PCM is located in the engine bay on the driver’s side, mounted to the inner fender or firewall.
Are any other procedures, like a security relearn, required?
For most vehicles of this era, a security relearn (often called Passlock or Passkey relearn) may be necessary after installation. This is a simple procedure that typically involves turning the key on and off in a specific sequence and can be done without special tools. We can provide instructions if needed.