If you’re dealing with frustrating engine problems in your 1999-2000 Pontiac Bonneville or another compatible GM vehicle, you know how quickly a simple drive can turn into a major headache. Intermittent stalling, a persistent check engine light, or a car that refuses to start can point directly to a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless drivers spend a fortune chasing symptoms when the root cause was the vehicle’s computer. This isn’t just a part; it’s the brain of your engine, and when it falters, everything else does too.
This is a dependable, tested, and used OEM Powertrain Control Module, part number 09361735. We take the guesswork and high cost out of the repair process. Before this module ships, we flash it with the latest GM software updates and program it specifically to your vehicle’s Vehicle Identification Number (VIN). This critical step ensures that it communicates perfectly with your car’s engine, transmission, and security systems right out of the box, saving you from a mandatory and expensive trip to the dealership for programming.
Diagnosing and Replacing Your 1999-2000 Bonneville PCM
A faulty PCM can create some of the most confusing diagnostic scenarios. You might experience issues that seem unrelated, from poor fuel economy to harsh transmission shifts. That’s because the PCM controls everything from fuel injector pulse width to ignition timing and transmission shift points. Replacing it with a correctly programmed unit is often the most direct path to restoring your vehicle’s original performance and reliability.
From the Diagnostic Bay
I remember a 1999 Pontiac Grand Prix—which uses this exact PCM—that came into my shop with a maddening intermittent no-start condition. The owner had already replaced the battery, starter, and crank sensor. It would run fine for days, then refuse to start, with no spark and no fuel pressure. After checking all the wiring, I noticed the problem only happened after the car sat in the sun. On a hunch, I used a heat gun on the PCM, and sure enough, the car wouldn’t start. A quick cool-down, and it fired right up. The internal circuits were failing when they got hot. We installed one of these VIN-programmed PCMs, and the customer never had the issue again. It’s a classic failure mode for these modules.
Common Signs of a Faulty GM PCM
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- ✔ The engine cranks but will not start.
- ✔ Intermittent stalling, especially when the engine is warm.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Unexplained loss of power or hesitation during acceleration.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- ✔ Locate the PCM: On most compatible models like the Bonneville, the PCM is located in the engine compartment on the driver’s side, often attached to the air filter box.
- ✔ Disconnect Connectors: Carefully release the locking tabs and unplug the electrical wiring harnesses from the old PCM. Avoid forcing them.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you may need to reuse it.
- ✔ Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it. Reconnect the wiring harnesses, ensuring they click securely into place.
- ✔ Reconnect Battery: Reattach the negative battery terminal.
- ✔ Perform Security Relearn: You may need to perform a simple security relearn procedure. Typically, this involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine. Consult your vehicle’s specific procedure if needed.
Verified Vehicle Compatibility
This module is a direct fit for a wide range of GM vehicles. Please verify your part number and application from the list below. This part is confirmed to fit the following models with the specified options:
- ✔ Bonneville: 1999, 2000 (3.8L VIN K)
- ✔ LeSabre: 1999-2000
- ✔ Park Avenue: 1999
- ✔ Riviera: 1999
- ✔ Eighty Eight: 1999
- ✔ Century: 1999
- ✔ Cutlass: 1999 (ID 9361735)
- ✔ Grand Prix: 1999, 2000 (3.8L)
- ✔ Impala: 2000 (3.4L & 3.8L)
- ✔ Intrigue: 1999
- ✔ Lumina Car: 1999
- ✔ Malibu: 1999 (3.1L)
- ✔ Monte Carlo: 1999-2000
- ✔ Regal: 1999
- ✔ Montana / Trans Sport: 1999
- ✔ Silhouette: 1999
- ✔ Venture: 1999
Do I need to do anything after I buy it?
Do I need to do anything after I buy it?
Yes. After your purchase, you must send us your vehicle’s 17-digit VIN. We cannot ship the module until we have your VIN to program it correctly. This ensures it works with your specific car.
Is this a new part?
No, this is a high-quality, tested used OEM part that has been sourced from a salvaged vehicle. Each unit is inspected for functionality before being programmed and shipped.
Why is VIN programming so important?
VIN programming loads your car’s specific software, including engine parameters, transmission settings, and anti-theft (VATS/Passlock) information. Without it, the car will not start or run correctly. Our service saves you from needing a dealership to perform this step.
Will I need special tools to install this?
No special tools are required for the physical installation, which typically only requires basic hand tools like a socket set. However, as noted in our guide, you will need to perform a security relearn procedure, which involves a sequence of key turns, not tools.
Is this part number 9361735 the same as 09361735?
Yes. In GM’s parts system, the leading zero is often omitted. Both part numbers refer to the exact same module. This listing is for service number 09361735.