Is Your GM Truck or Van Experiencing Mysterious Problems?
If your 1998-1999 Chevrolet or GMC vehicle is suffering from issues like poor engine performance, erratic shifting, a no-start condition, or a persistent Check Engine Light with confusing codes, the culprit is often a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can create a cascade of problems that are difficult to diagnose. This pre-programmed PCM is the direct-fit, reliable solution to get your workhorse back on the road and running smoothly.
From the Diagnostic Bay
I once had a 1999 Chevy Suburban come in with a complaint of harsh, unpredictable transmission shifting. The owner had already spent a small fortune replacing the transmission, but the problem persisted. After hooking up the scan tool, I noticed erratic data coming from the PCM and communication dropouts. We swapped in a known-good, correctly programmed PCM, and the truck shifted perfectly. It wasn’t a mechanical transmission failure at all; the computer was simply sending the wrong signals. This highlights how crucial a fully functional PCM is for the entire vehicle’s operation.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various, sometimes unrelated, trouble codes (DTCs).
- ✔ Vehicle fails to start or starts intermittently.
- ✔ Poor fuel economy and noticeable loss of power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, stuttering, or misfiring for no apparent reason.
- ✔ Failure to communicate with a diagnostic scan tool.
The Plug-and-Play Solution for Your 1998-1999 Savana 3500 PCM
Replacing the PCM on these classic GM trucks and vans used to mean a trip to the dealership for expensive programming. We’ve eliminated that step. This is a genuine, used GM PCM sourced from a salvaged vehicle, which we then program specifically for your vehicle using your VIN. We load the latest GM-certified software updates, ensuring optimal performance and compatibility. When you receive the module, it’s ready for installation. This process saves you time, money, and the hassle of towing your vehicle to a service center.
Simple Installation Process
Installation is straightforward for anyone with basic mechanical skills. The PCM is typically located in the engine compartment. Simply disconnect the vehicle’s battery, carefully unplug the wiring harnesses from the old module, unbolt it, and install the new one in its place. Reconnect the harnesses and the battery. In many cases, the vehicle will start and run immediately. Some vehicles may require a security relearn or Crankshaft Variation (CASE) relearn procedure, which can often be performed without specialized tools. Instructions for these procedures are widely available online for your specific model.
Guaranteed Fitment
This module is a direct replacement for several part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. Please verify your part number before ordering. This part will fit the following makes and models with matching options:
CHEVROLET 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
CHEVROLET 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
EXPRESS 1500 VAN 98-99 Electronic Control Module; ID 9355699
EXPRESS 2500 VAN 98-99 Electronic Control Module; gasoline, ID 9355699
EXPRESS 3500 VAN 98-99 Electronic Control Module; gasoline, ID 9355699
GMC 1500 PICKUP 98-99 Electronic Control Module; gasoline (LH engine compartment), ID 9355699
GMC 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
GMC 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
SAVANA 1500 VAN 98-99 Electronic Control Module; ID 9355699
SAVANA 2500 VAN 98-99 Electronic Control Module; gasoline, ID 9355699
SAVANA 3500 VAN 98-99 Electronic Control Module; gasoline, ID 9355699
SUBURBAN 1500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
SUBURBAN 2500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
TAHOE 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
YUKON 98-99 Electronic Control Module; (LH engine compartment), ID 9355699
ESCALADE 99 Electronic Control Module; (LH front engine compartment), ID 9355699
ASTRO 98 Electronic Control Module; (LH front by battery), ID 9355699
SAFARI (GMC) 98 Electronic Control Module; (LH front by battery), ID 9355699
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/o build date opt ZN4; ID 9355699
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/o build date opt ZN4; ID 9355699
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/o extended build date opt ZN4; ID 9355699
Frequently Asked Questions
Do I need to have this computer programmed?
No. We handle all the programming for you before shipment. Simply provide us with your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the latest GM software specific to your vehicle.
Is this a new part?
No, this is a high-quality, tested used part sourced from a salvaged vehicle. This allows us to offer a reliable, genuine GM component at an excellent value.
What is a CASE Relearn and will I need to do it?
A CASE (Crankshaft Position System Variation) Relearn is a procedure that allows the PCM to learn the minor variations in the crankshaft position sensor. After installing a new PCM, this procedure may be required to clear certain trouble codes (like P1336) and ensure accurate misfire detection. On many of these vehicles, it can be done without a scan tool by following a specific driving procedure.
How do I provide my VIN?
You can add your VIN in the notes section during checkout or send it to us in a message after you complete your purchase. We cannot ship your order until we receive your VIN, as the programming is essential.
Will this fix my transmission shifting problems?
A failing PCM is a very common cause of erratic shifting, failure to shift, or harsh engagement on these GM vehicles. While we cannot guarantee it will solve every transmission issue, it is a critical diagnostic step and a frequent solution for electronically-controlled transmission problems.