Is Your Savana Van Running Rough? The PCM Might Be the Culprit.
If your 1998 or 1999 GMC Savana 3500 is experiencing perplexing issues like stalling, erratic shifting, a persistent check engine light, or even a complete no-start condition, the problem may lie with its electronic brain: the Powertrain Control Module (PCM). This critical component is responsible for managing everything from fuel injection and ignition timing to transmission shift points. When it fails, it can cause a cascade of problems that are often misdiagnosed, leading to costly and unnecessary repairs.
The Smart, Reliable Solution for Your Vehicle
Instead of gambling on an unprogrammed module from a junkyard or paying dealership prices, our service offers the perfect solution. This is a genuine, used OEM Powertrain Control Module that has been thoroughly inspected and is ready to be programmed specifically for your van. We take the guesswork out of the repair by flashing the unit with the latest GM-certified software updates using your vehicle’s unique Vehicle Identification Number (VIN). This ensures that the module communicates flawlessly with all other systems in your van, restoring its original performance and reliability.
From the Diagnostic Bay
I once had a 1999 Express van, which uses this exact same PCM, come into the shop on a tow hook. It would crank all day but wouldn’t fire up. The owner had already spent a fortune replacing the fuel pump and crank sensor based on another shop’s advice. Before condemning the computer, I ran a quick voltage drop test on the main power and ground circuits for the PCM. Sure enough, a corroded ground wire on the engine block was causing an intermittent connection. A ten-minute fix with a wire brush and some dielectric grease saved the customer from buying a computer he didn’t need. It’s a powerful reminder: always verify your main power and grounds before replacing any module!
Common Symptoms of a Failing 1998-1999 Savana 3500 PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling unexpectedly or for no apparent reason.
- ✔ Rough idling or misfires.
- ✔ Vehicle refuses to start, even with a good battery and starter.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or delayed automatic transmission shifting.
- ✔ Failure to communicate with diagnostic scan tools.
- ✔ Inaccurate or non-functioning dashboard gauges.
Plug-and-Play Installation Process
Our goal is to make your repair as simple as possible. After you place your order, you will need to provide us with your van’s VIN. Our technicians will then program this module, ensuring it’s a perfect match for your vehicle’s specific configuration. When you receive the part, installation is straightforward. In most cases, you will need to perform a security relearn procedure (often called a CASE relearn or Passlock relearn) after installation, which can typically be done without specialized tools. This simple procedure syncs the new module with your vehicle’s anti-theft system.
Guaranteed Fitment for Multiple GM Models
This versatile electronic control module, identified by part numbers 16266645 and service ID 09355699, is a direct replacement for a wide range of GM trucks and vans from 1998 and 1999. Please verify your vehicle is on the list below. Our VIN-based programming ensures compatibility.
This part will fit these makes and models with these options:
This part will fit these makes and models with these options:
ASTRO 98 (LH front by battery)
BLAZER S10/JIMMY S15 98 (RH front engine compartment), w/o build date opt ZN4
BRAVADA 98 (6-262, 4.3L), w/o build date opt ZN4
CHEVROLET 1500 PICKUP 98-99 (gasoline, LH front engine compartment)
CHEVROLET 2500 PICKUP 98-99 (gasoline, LH front engine compartment)
CHEVROLET 3500 PICKUP 98-99 (gasoline, LH front engine compartment)
ENVOY 98 (RH front engine compartment), w/o build date opt ZN4
ESCALADE 99 (LH front engine compartment)
EXPRESS 1500 VAN 98-99
EXPRESS 2500 VAN 98-99 (gasoline)
EXPRESS 3500 VAN 98-99 (gasoline)
GMC 1500 PICKUP 98-99 (gasoline, LH engine compartment)
GMC 2500 PICKUP 98-99 (gasoline, LH front engine compartment)
GMC 3500 PICKUP 98-99 (gasoline, LH front engine compartment)
ISUZU HOMBRE 98 4.3L (6 cylinder), w/o extended build date opt ZN4
S10/S15/SONOMA 98 6-262 (4.3L), w/o build date opt ZN4
SAFARI (GMC) 98 (LH front by battery)
SAVANA 1500 VAN 98-99
SAVANA 2500 VAN 98-99 (gasoline)
SAVANA 3500 VAN 98-99 (gasoline)
SUBURBAN 1500 98-99 (gasoline, LH front engine compartment)
SUBURBAN 2500 98-99 (gasoline, LH front engine compartment)
TAHOE 98-99 (gasoline, LH front engine compartment)
YUKON 98-99 (LH engine compartment)
Frequently Asked Questions
This part will fit these makes and models with these options:
ASTRO 98 (LH front by battery)
BLAZER S10/JIMMY S15 98 (RH front engine compartment), w/o build date opt ZN4
BRAVADA 98 (6-262, 4.3L), w/o build date opt ZN4
CHEVROLET 1500 PICKUP 98-99 (gasoline, LH front engine compartment)
CHEVROLET 2500 PICKUP 98-99 (gasoline, LH front engine compartment)
CHEVROLET 3500 PICKUP 98-99 (gasoline, LH front engine compartment)
ENVOY 98 (RH front engine compartment), w/o build date opt ZN4
ESCALADE 99 (LH front engine compartment)
EXPRESS 1500 VAN 98-99
EXPRESS 2500 VAN 98-99 (gasoline)
EXPRESS 3500 VAN 98-99 (gasoline)
GMC 1500 PICKUP 98-99 (gasoline, LH engine compartment)
GMC 2500 PICKUP 98-99 (gasoline, LH front engine compartment)
GMC 3500 PICKUP 98-99 (gasoline, LH front engine compartment)
ISUZU HOMBRE 98 4.3L (6 cylinder), w/o extended build date opt ZN4
S10/S15/SONOMA 98 6-262 (4.3L), w/o build date opt ZN4
SAFARI (GMC) 98 (LH front by battery)
SAVANA 1500 VAN 98-99
SAVANA 2500 VAN 98-99 (gasoline)
SAVANA 3500 VAN 98-99 (gasoline)
SUBURBAN 1500 98-99 (gasoline, LH front engine compartment)
SUBURBAN 2500 98-99 (gasoline, LH front engine compartment)
TAHOE 98-99 (gasoline, LH front engine compartment)
YUKON 98-99 (LH engine compartment)