Restore Your Van’s Core Performance and Reliability
Is your 1998 or 1999 GMC Savana 1500 van running rough, stalling unexpectedly, or showing a persistent Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your engine and transmission. A faulty PCM can cause a cascade of frustrating issues, from poor fuel economy to a complete no-start condition. This isn’t just an inconvenience; it’s a reliability problem that can leave you stranded. We offer a dependable and straightforward solution: a genuine, used GM PCM that is professionally programmed to your vehicle’s specific VIN before it ships.
A Technician’s Notebook: The Intermittent Gremlin
I remember a 1999 Express van—nearly identical to the Savana—that came into my bay with the weirdest symptoms. The owner said it would randomly lose power and the transmission would get stuck in one gear, but only on hot days after driving for 30+ minutes. We couldn’t replicate it at first. No hard codes, just a history of communication loss. After checking all the wiring harnesses for heat damage, we decided to swap in a known-good PCM. The problem vanished instantly. The original module’s internal processor was failing under thermal stress, a common issue I’ve seen on dozens of these older GM computers. Replacing the PCM was the only permanent fix.
Is Your GM Vehicle Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is likely the solution you need. This is especially true if you have diagnostic trouble codes (DTCs) pointing to an internal module failure.
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- ✔ Vehicle refuses to start or stalls intermittently for no apparent reason.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Misfires or rough idling that can’t be traced to spark plugs or coils.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Installation
Replacing the 1998-1999 Savana 1500 PCM is a job most DIYers can handle in their own driveway. Since we program the module beforehand, you avoid a costly trip to the dealership. While a security relearn procedure may be necessary, it’s a simple process you can do yourself.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for the system to discharge.
- Locate the PCM: On the Savana/Express vans, the PCM is typically located in the engine compartment, on the left-hand (driver’s) side, near the rear of the engine bay.
- Disconnect Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware as you will reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): Turn the key to the ‘ON’ position (without starting) for 10-15 minutes. Turn it ‘OFF’ for 10 seconds. Repeat this cycle 2-3 times. This allows the vehicle’s security system to recognize the new PCM. Your van should now start and run correctly.
Will This Fit My Vehicle?
This PCM, identified by part number 09355699, is a direct replacement for a wide range of GM trucks and vans. Please verify your vehicle is on this list and that your original module carries one of the compatible part numbers: 09355699, 16266645, 16250279, 16258815, or 09366810.
Blazer S10/Jimmy S15: 1998 (RH front engine compartment, w/o build date opt ZN4)
Bravada: 1998 (w/o build date opt ZN4)
Cadillac Escalade: 1999 (LH front engine compartment)
Chevrolet/GMC 1500 Pickup: 1998-1999 (Gasoline, LH engine compartment)
Chevrolet/GMC 2500 Pickup: 1998-1999 (Gasoline, LH front engine compartment)
Chevrolet/GMC 3500 Pickup: 1998-1999 (Gasoline, LH front engine compartment)
Envoy: 1998 (RH front engine compartment, w/o build date opt ZN4)
Express/Savana 1500 Van: 1998-1999
Express/Savana 2500 Van: 1998-1999 (Gasoline)
Express/Savana 3500 Van: 1998-1999 (Gasoline)
Isuzu Hombre: 1998 (4.3L, w/o extended build date opt ZN4)
S10/S15/Sonoma Pickup: 1998 (4.3L, w/o build date opt ZN4)
Safari Van: 1998 (LH front by battery)
Suburban 1500: 1998-1999 (Gasoline, LH front engine compartment)
Suburban 2500: 1998-1999 (Gasoline, LH front engine compartment)
Tahoe/Yukon: 1998-1999 (Gasoline, LH engine compartment)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact factory software and calibrations for your specific engine, transmission, and options. This ensures perfect compatibility and performance right out of the box.
Is this a new part?
No, this is a high-quality, tested used part sourced from a salvaged vehicle. This provides a reliable, OEM-grade solution at a fraction of the cost of a new module from a dealership.
Will I need to do anything after installation?
In most cases, you will need to perform a simple security relearn procedure, which involves cycling the ignition key. We provide instructions for this process. It requires no special tools and ensures your vehicle’s anti-theft system works correctly with the replacement PCM.
What if my original part number is slightly different?
This module replaces several part numbers, including 16266645, 16250279, and others listed above. As long as your vehicle is on the fitment list and your part is one of the alternates, this module will work correctly once programmed to your VIN.
How do I provide my VIN?
After you complete your purchase, simply send us a message with your 17-digit VIN. We cannot ship your order until we receive this information, as the programming is a critical part of the process.