Restore Your GM’s Reliability and Performance
If you’re dealing with frustrating issues like your 1998 Buick Riviera stalling, running rough, or refusing to start, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your engine, its health is critical for everything from fuel mixture to transmission shifting. This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra expense out of the repair by programming this module specifically for your vehicle using your VIN. This ensures it has the latest GM software updates for optimal performance and efficiency, right out of the box.
From the Diagnostic Bay: The Phantom No-Start
I remember a 1998 Buick LeSabre with the 3.8L V6 that came into my shop on a tow truck. The owner had already replaced the battery and crank sensor, but it would only crank, never start. The scan tool wasn’t showing any crank signal codes, which was puzzling. After checking for fuel pressure and spark—both were weak and erratic—I focused on the PCM. By back-probing the PCM connectors, I found the 5-volt reference signal was dropping out intermittently. The internal voltage regulator in the original PCM was failing, a common issue on these units after 20+ years. Installing a properly programmed 1998 Riviera Powertrain Control Module like this one provided a stable signal and the car fired up on the first try. It’s a reminder that sometimes the problem lies with the brain, not the sensors.
Is Your Vehicle Showing These Symptoms?
A failing PCM can cause a wide range of confusing symptoms. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Unexplained Check Engine Light (CEL) with codes like P0601, P0605, or other communication errors.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ A no-start or hard-start condition, especially when warm.
- ✔ Decreased fuel economy and poor engine performance.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent failure of fuel injectors or ignition coils to fire.
A Straightforward Guide to Installation
Replacing your 1998 Riviera Powertrain Control Module is a job most DIYers can handle. We do the complex programming; you just need a few basic tools.
- 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 vehicles, the PCM is located in the engine bay, often inside the air filter box assembly or mounted to the firewall.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old module. They have locking tabs, so be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Secure your new, pre-programmed PCM onto the mounting bracket and reconnect the wiring harnesses. Ensure they click securely into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn: You MUST perform a simple key-on/key-off security relearn procedure. This syncs the new PCM with your vehicle’s anti-theft system. A typical procedure is: Turn the key to ‘ON’ for 10 minutes, ‘OFF’ for 10 seconds, and repeat two more times. The vehicle should then start.
Verified Vehicle Compatibility
This module, part number 9356741, is a direct-fit replacement for a wide range of GM vehicles. It is compatible with service numbers 09356741, 16236757, 9357034, 9357440, and 9366314. Please confirm your vehicle is on the list below:
- ACHIEVA 1998 (3.1L)
- ALERO 1999 (3.4L, check service ID)
- BONNEVILLE 1998
- CAMARO 1998 (3.8L)
- CENTURY 1998 (3.1L)
- CUTLASS 1998-1999 (check service ID for ’99)
- EIGHTY EIGHT 1998
- FIREBIRD 1998 (3.8L)
- GRAND AM 1998 (3.1L), 1999 (3.4L, check service ID)
- GRAND PRIX 1998
- INTRIGUE 1998
- LESABRE 1998 (3.8L)
- LUMINA CAR 1998
- MALIBU 1998 (3.1L)
- MONTE CARLO 1998
- PARK AVENUE 1998 (3.8L)
- REGAL 1998
- RIVIERA 1998 (3.8L)
- SILHOUETTE 1998
- SKYLARK 1998 (3.1L)
- TRANS SPORT 1998
- VENTURE 1998 (3.4L)
This is the definitive fix for your classic GM car. By providing your VIN at checkout, you ensure a plug-and-play repair that restores the function and reliability you depend on. Don’t let a faulty computer keep you off the road—get the right part, programmed correctly, the first time.
Frequently Asked Questions about this PCM
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the module with the exact software and calibrations your vehicle requires. This includes engine size, transmission type, and any specific options, ensuring perfect compatibility and performance.
Is this a simple plug-and-play installation?
Almost. We handle all the programming, so you won’t need a scan tool. However, after installation, you must perform a standard GM security relearn procedure, which takes about 30 minutes using only your ignition key. We provide instructions for this simple process.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (like DTC P0601), this module will resolve the issue. It’s crucial to properly diagnose the problem first, as the light could be on for other reasons, such as a bad sensor.
What’s the difference between a PCM, ECM, and ECU?
The terms are often used interchangeably. PCM (Powertrain Control Module) is most accurate for these GM vehicles as it controls both the engine (Engine Control Module – ECM) and the automatic transmission functions. ECU (Electronic Control Unit) is a more generic term.
Is this part difficult to locate on my vehicle?
On most of the compatible models, the PCM is quite accessible. It’s typically found inside the air cleaner housing or mounted to the firewall in the engine compartment. A quick search for your specific model will usually show its exact location.