Is Your GM Truck or SUV Running Rough? The PCM Might Be the Culprit.
If you’re dealing with frustrating issues like a persistent check engine light, poor fuel economy, erratic shifting, or even a no-start condition in your 1998 Oldsmobile Bravada or other compatible GM vehicle, a failing Powertrain Control Module (PCM) is a very likely cause. The PCM is the electronic brain of your vehicle, orchestrating everything from fuel injection and spark timing to transmission shift points and emissions controls. When it begins to fail, it can create a cascade of problems that are often difficult to diagnose, leading to wasted time and money on unnecessary parts.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take a quality, road-tested OEM computer and program it specifically to your vehicle’s Vehicle Identification Number (VIN). This critical step ensures that the module has the correct software and calibrations for your engine, transmission, and specific options. We flash it with the latest available updates from GM, which can often resolve factory bugs and improve overall performance and drivability. By providing us with your VIN after purchase, you eliminate the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
I once had a 1999 Chevy Tahoe in the shop that was driving the owner crazy. It had a random, intermittent stalling issue and a check engine light for an O2 sensor heater circuit. The owner had already replaced the O2 sensor twice, along with the spark plugs and wires, with no luck. After hooking up the scanner and watching the live data, I noticed the voltage on that specific O2 heater circuit was fluctuating wildly. Instead of chasing the sensor again, I went straight to the PCM wiring diagram. A quick check at the PCM connector confirmed the wiring was good. The problem was internal to the PCM; the driver circuit for that O2 sensor was failing. We installed a VIN-programmed PCM just like this one, performed the security relearn, and the Tahoe ran perfectly. It’s a classic case where the root cause was the computer, not the parts it was controlling.
Diagnosing a Faulty 1998 Bravada PCM
A failing engine computer can manifest in numerous ways, often mimicking other component failures. If you’re experiencing several of the following symptoms, it’s a strong indicator that your PCM needs attention.
- ✔ Check Engine Light: The light is on, and you may have codes related to sensor circuits (e.g., P0135, P0443), internal module memory errors (P0601), or communication errors (U-codes).
- ✔ No-Start or Hard-Start: The engine cranks but refuses to start, or takes an unusually long time to fire up, either hot or cold.
- ✔ Engine Stalling: The vehicle stalls unexpectedly while driving or when coming to a stop.
- ✔ Poor Performance & Fuel Economy: You may notice a significant drop in power, hesitation during acceleration, and a noticeable decrease in your miles per gallon.
- ✔ Harsh or Erratic Shifting: The transmission may shift hard, slip between gears, or get stuck in one gear (limp mode).
- ✔ Inconsistent Instrument Cluster Behavior: Gauges may act erratically or not work at all.
- ✔ Failed Emissions Test: A faulty PCM can prevent the vehicle’s emissions monitors from running, resulting in an automatic failure.
The Plug-and-Play Advantage
The single biggest hurdle when replacing a modern vehicle’s computer is the programming. This unit removes that obstacle. Sourced from a salvaged vehicle and rigorously tested for full functionality, this OEM module is a reliable and cost-effective alternative to a new part. By programming it to your VIN before it ships, we ensure it communicates correctly with the other modules in your vehicle, like the Body Control Module and ABS module. Once installed, the only remaining step is a simple security relearn procedure (often called Passlock or Passkey relearn), which you can typically do yourself in your driveway without any special tools. This process syncs the new PCM to your vehicle’s anti-theft system, allowing the engine to start and run.
This PCM is a direct replacement for multiple part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. It fits a wide array of popular GM trucks, vans, and SUVs from the late 1990s, such as the Chevrolet Silverado, GMC Sierra, Tahoe, Yukon, Suburban, S10, Blazer, and Express/Savana vans. Please verify the part number ID 09355699 in the detailed fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to have this computer programmed?
No. We handle the programming for you before we ship the part. Simply provide us with your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the correct GM software for your specific vehicle.
What other steps are required after installation?
After installing the PCM, you will need to perform a security relearn procedure. This is a simple process that syncs the new computer with your vehicle’s anti-theft system. It typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating this sequence three times. Instructions for this can be easily found online for your specific model.
Is this a new part?
No, this is a high-quality, tested used OEM part sourced from a salvaged vehicle. This ensures perfect factory fitment and function at a fraction of the cost of a new unit. Each module is inspected and verified to be in good working condition before being programmed.
Where can I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on a metal plate on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this part will resolve the issue. However, it’s crucial to properly diagnose the vehicle first, as the check engine light can be triggered by many other failing components. This PCM will fix issues related to internal module failure or faulty sensor driver circuits.