Restore Peak Performance to Your GM Van or Truck
Is your Chevrolet Express or GMC Savana van running rough, stalling unexpectedly, or showing a persistent Check Engine Light? These are classic signs of a failing Powertrain Control Module (PCM), the electronic brain of your vehicle’s engine. A faulty PCM can cause a host of frustrating issues, from poor fuel mileage and failed emissions tests to harsh shifting and even a no-start condition. This reliable, tested PCM, part number 9366810, is the definitive solution to get your workhorse back on the road and running smoothly.
A Technician’s Notebook
I remember a 1999 Savana 2500 that came into the shop with a problem that drove the owner crazy. It would randomly stall at red lights, but only when the engine was warm. There were no consistent codes, just an occasional generic misfire. We checked fuel pressure, spark, and sensors—all were fine. On a hunch, I monitored the PCM data stream and noticed the injector pulse width would suddenly drop to zero right before a stall. We swapped in a tested, correctly programmed PCM like this one, and the problem vanished. It’s a perfect example of how an internal PCM fault can create phantom issues that are nearly impossible to trace elsewhere.
Is Your Vehicle Showing These Symptoms?
- ✔ Check Engine Light is on with codes like P0601, P0602, or P0606 (Internal Control Module Errors).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ The transmission is shifting erratically or harshly.
- ✔ Stalling, stuttering, or hesitation during acceleration.
- ✔ Failure to pass state emissions testing.
The Smart Solution: Pre-Programmed for Your Vehicle
Don’t waste time and money at a dealership. We take the hassle out of the replacement process. Before we ship this module, our technicians will program it with the latest GM software updates specifically for your vehicle’s Vehicle Identification Number (VIN). This ensures that it communicates perfectly with your engine, transmission, and all related systems right out of the box. This 1998-1999 Express 2500 PCM arrives ready to install, saving you from needing expensive proprietary scan tools or a trip to the dealer for programming.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting work.
- ✔ Locate the PCM: On most GM vans and trucks from this era, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- ✔ Disconnect Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. There are usually several multi-pin connectors with locking tabs.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new module.
- ✔ Install the New PCM: Mount the new, programmed PCM onto the bracket and securely fasten it.
- ✔ Reconnect Everything: Plug the wiring harness connectors firmly into the new module. Reconnect the negative battery terminal.
- ✔ Perform Security Relearn: After installation, you may need to perform a security relearn procedure (often called CASE learn or Passlock relearn) for the vehicle to start. This procedure can typically be done without special tools and instructions are widely available online for your specific model.
Verified Vehicle Compatibility
This module is a direct replacement for service number 9366810 and other interchangeable part numbers like 09355699, 16266645, 16250279, and 16258815. It is guaranteed to fit a wide range of 1998-1999 GM trucks and vans. Please verify your vehicle is on the list below and that your original part number matches.
- ASTRO 98
- BLAZER S10/JIMMY S15 98
- BRAVADA 98
- CADILLAC ESCALADE 99
- CHEVROLET 1500 PICKUP 98-99
- CHEVROLET 2500 PICKUP 98-99 (Gas)
- CHEVROLET 3500 PICKUP 98-99 (Gas)
- ENVOY 98
- EXPRESS 1500 VAN 98-99
- EXPRESS 2500 VAN 98-99 (Gas)
- EXPRESS 3500 VAN 98-99 (Gas)
- GMC 1500 PICKUP 98-99
- GMC 2500 PICKUP 98-99 (Gas)
- GMC 3500 PICKUP 98-99 (Gas)
- ISUZU HOMBRE 98 (4.3L)
- S10/S15/SONOMA 98 (4.3L)
- SAFARI (GMC) 98
- SAVANA 1500 VAN 98-99
- SAVANA 2500 VAN 98-99 (Gas)
- SAVANA 3500 VAN 98-99 (Gas)
- SUBURBAN 1500 98-99 (Gas)
- SUBURBAN 2500 98-99 (Gas)
- TAHOE 98-99 (Gas)
- YUKON 98-99
Frequently Asked Questions
Do I need to do anything after I install this PCM?
Because this PCM is pre-programmed to your VIN, no dealer flashing is required. However, on many GM vehicles, you will need to perform a security relearn procedure (like Passlock or CASE learn) so the vehicle’s anti-theft system recognizes the new computer. This can usually be done in your driveway and takes 10-30 minutes.
How do I provide my VIN?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship the module without it.
Is a used PCM reliable?
Absolutely. This is a genuine OEM part that has been sourced from a salvaged vehicle and thoroughly inspected. We then load it with the latest factory software for your vehicle. This provides OEM-level reliability at a fraction of the cost of a new part from a dealer.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine functions and transmission shift points. If the module is failing, it can send incorrect signals to the transmission, causing harsh or erratic shifting. Replacing a faulty PCM often resolves these types of transmission issues.
How do I find my original part number?
Your vehicle’s original part number is printed on a sticker on the PCM itself. You will need to locate the module in your engine bay to physically inspect it and confirm the number.