Restore Your Van’s Brain and Get Back to Work
Is your 1998 or 1999 Chevy Express or GMC Savana van running rough, stalling unexpectedly, or refusing to start? Are you chasing frustrating electrical gremlins and a persistent Check Engine Light? Before you spend another weekend replacing perfectly good sensors, the problem might be the very heart of your vehicle’s electronics: the Powertrain Control Module (PCM). As the central computer, a failing PCM can cause a cascade of issues that mimic other part failures. This genuine, used OEM PCM, part number 09355699, is the reliable and cost-effective solution to get your workhorse back on the road.
We take the guesswork and hassle out of the replacement process. Unlike a generic module from a junkyard, each unit we ship is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures all factory settings for your engine, transmission, and emissions equipment are correctly loaded. We flash it with the latest GM software updates, which can resolve issues the original programming may have had. The result is a module that is ready for installation right out of the box, saving you a costly trip to the dealership for programming.
Case Study: The Ghost in the Machine
I remember a 1999 Suburban that came into my shop a few years back. The owner had replaced the throttle position sensor, the mass airflow sensor, and even the fuel pump. It would still randomly stall at red lights and had a terrible hesitation on acceleration. The scanner wasn’t showing consistent sensor faults, just a generic P0601 internal memory error that would come and go. After verifying the wiring was solid, we swapped in a VIN-programmed PCM like this one. The difference was immediate. The engine smoothed out, the stalling stopped, and the power returned. It’s a classic scenario for these GM trucks and vans—the internal components of the original PCM simply wear out over time, causing unpredictable and frustrating problems.
Key Symptoms of a Failing PCM
- ✔ Check Engine Light is on with communication error codes like P0601, P0605, or U-series codes.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough, erratic idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Failure to pass an emissions test.
- ✔ Other modules on the vehicle not communicating with the scan tool.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- ✔ Locate the PCM: On most of these GM vans and trucks, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- ✔ Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old PCM. Inspect them for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in by a few bolts.
- ✔ Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- ✔ Reconnect Everything: Plug the electrical connectors firmly into the new module. Reconnect the negative battery terminal.
- ✔ Perform Security Relearn: You will likely need to perform a simple security relearn procedure (often called a Passlock or Passkey relearn). This typically involves turning the key to ‘ON’ for 10-15 minutes, then ‘OFF’, and repeating a couple of times until the security light goes out. This syncs the new PCM with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This module is a direct replacement for service number 09355699 and is interchangeable with part numbers 16266645, 16250279, 16258815, and 09366810. It fits a wide range of 1998-1999 GM trucks, vans, and SUVs. Please match your part number or confirm your vehicle is on the list below to ensure proper fitment.
Fits select 1998-1999 models of:
- ✔ Chevrolet Express / GMC Savana Vans (1500, 2500, 3500)
- ✔ Chevrolet / GMC Pickups (1500, 2500, 3500)
- ✔ Chevrolet Suburban / Tahoe & GMC Yukon
- ✔ Cadillac Escalade
- ✔ Chevrolet Astro / GMC Safari
- ✔ Chevrolet S10 / GMC Sonoma
- ✔ Chevrolet Blazer / GMC Jimmy
- ✔ Oldsmobile Bravada
- ✔ Isuzu Hombre
Note: It is crucial to provide your VIN upon purchase so we can program the module specifically for your vehicle’s engine, transmission, and options.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) contains critical information about your specific vehicle, including the engine size, transmission type, and factory options. We use the VIN to load the exact GM-certified software onto the PCM, ensuring it communicates perfectly with your vehicle’s systems for optimal performance and a seamless installation.
Is this part difficult to install myself?
The physical installation is straightforward for most DIY mechanics, typically involving just a few bolts and electrical connectors. The most important step after installation is the security relearn procedure, which can usually be done without special tools. We recommend searching for the specific ‘Passlock relearn’ procedure for your model year.
Is this a new part?
No, this is a high-quality, tested, used OEM (Original Equipment Manufacturer) part sourced from a salvaged vehicle. This allows us to offer a reliable, factory-spec part at a significant savings compared to a new unit from a dealer.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like code P0601), then yes, this part will resolve the issue. However, it’s always best to have your vehicle properly diagnosed to ensure the PCM is the root cause and not a faulty sensor or wiring problem.