Restore Peak Performance to Your GM Truck or Van
If you’re dealing with frustrating issues like stalling, a persistent check engine light, or a vehicle that just won’t start, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over 20 years of experience under the hood, I’ve seen how a faulty computer can mimic a dozen other problems, leading to wasted time and money on unnecessary repairs. This isn’t just a replacement part; it’s a reliable, cost-effective solution to get your vehicle running right again. This is a genuine, used OEM 1999 Escalade PCM that has been meticulously tested and is ready for a new life in your vehicle.
The real value here is our professional programming service. Before we ship it, we flash the module with your vehicle’s specific VIN and the latest software updates from General Motors. This critical step ensures seamless communication between the engine, transmission, and other systems, eliminating the need for an expensive trip to the dealership for programming. You get a part that’s truly ready for installation right out of the box.
A Technician’s Notebook: The Phantom Transmission Problem
I once had a 1999 GMC Yukon in my bay with severe, harsh shifting. The owner was convinced his transmission was shot and had already spent a small fortune on fluid changes and diagnostics at other shops. He was ready to buy a new transmission. However, his scan tool showed no transmission-specific codes, just a generic P0605 (PCM Read Only Memory Error). On a hunch, we swapped in a known-good, correctly programmed PCM. The difference was immediate. The shifts became smooth as silk. The original PCM’s internal processor was failing, corrupting the signals sent to the transmission solenoids. This single part saved him thousands of dollars and a massive headache. It’s a classic example of why correctly diagnosing and replacing the PCM is crucial.
Is Your Truck’s Brain Failing? Common Symptoms
A failing PCM can cause a wide range of confusing symptoms. If your vehicle is experiencing any of the following, this module could be the solution you need:
- ✔ Unexplained Check Engine Light (CEL) with codes like P0601, P0602, P0605, or U-series communication codes.
- ✔ Engine stalling, sputtering, or refusing to start.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle enters a “limp mode,” with reduced power.
- ✔ Intermittent issues that seem to have no pattern.
A Straightforward Guide to Installation
Installing your programmed 1999 Escalade PCM is a job most DIYers can handle with basic tools. Following these steps will ensure a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the PCM: On most of these GM trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harness connectors from the old module. Inspect the pins 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 small bolts.
- 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 until they click into place. Reconnect the negative battery terminal.
- Final Step: Some vehicles may require a security relearn procedure, which can often be done by cycling the key. Consult your vehicle’s service information if needed. Start the engine and enjoy a smoother-running vehicle!
Verified Fitment for a Wide Range of GM Trucks & Vans
This module, identified by part number 9355699, is a direct replacement for a vast number of popular GM vehicles. Please verify your original part number or match your vehicle in the list below. This part is compatible with service numbers 09355699, 16266645, 16250279, 16258815, 09366810, and 9366810.
Fits models including, but not limited to:
- Cadillac Escalade (1999)
- Chevrolet & GMC Pickups (1500, 2500, 3500) (1998-1999)
- Chevrolet & GMC Suburban (1500, 2500) (1998-1999)
- Chevrolet Tahoe & GMC Yukon (1998-1999)
- Chevrolet Express & GMC Savana Vans (1500, 2500, 3500) (1998-1999)
- Chevrolet Astro & GMC Safari Vans (1998)
- Chevrolet S10/Blazer & GMC Sonoma/Jimmy (1998)
- Oldsmobile Bravada & GMC Envoy (1998)
- Isuzu Hombre (1998)
Frequently Asked Questions
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, correct software from GM for your vehicle’s specific engine, transmission, and options. This ensures it works perfectly upon installation without needing dealer programming.
Is this part difficult to install?
No, this is a straightforward replacement. Since we program it beforehand, you simply need to disconnect the battery, unbolt the old module, and plug this one in. It’s a great project for a confident DIYer.
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 will resolve the issue. It’s important to properly diagnose the cause of the light before ordering to ensure the PCM is the faulty component.
Is this a new part?
This is a high-quality, tested, and guaranteed used OEM part sourced from a salvaged vehicle. We find that genuine OEM electronics offer superior reliability compared to many aftermarket alternatives.
My original part number isn’t 9355699, but it’s on the interchange list. Will this work?
Yes. The part numbers on our interchange list (like 16266645, 16250279, etc.) are all functionally identical and fully compatible. As long as your number is on our list, this module will work perfectly once programmed to your VIN.