Is Your GM Vehicle Acting Possessed? The PCM Might Be the Culprit.
As a technician with over two decades of experience, I’ve seen it all. A car comes into the bay with a laundry list of bizarre, unrelated symptoms: the transmission bangs into gear one minute and shifts smoothly the next, the engine randomly stalls at a stoplight, or the check engine light throws codes for sensors you just replaced. For many late-90s GM vehicles, like your 1998 Buick Riviera, these ghost-in-the-machine problems often trace back to one single component: a failing Powertrain Control Module (PCM).
A Real-World Scenario from My Shop
“A customer’s 1998 Pontiac Grand Prix came in last week with these exact symptoms. He’d already replaced the throttle position sensor and a transmission solenoid based on the codes, but the harsh 1-2 shift and intermittent stalling persisted. We connected our diagnostic scanner and saw erratic data streams coming from the PCM. After confirming power and grounds were good, we knew the module itself was the issue. We installed a VIN-programmed PCM, performed the security relearn, and the car drove out shifting perfectly, with all the ghost codes gone. It’s a classic failure mode for these units.”
Common Symptoms of a Failing GM PCM (Part #9357440)
The PCM is the brain of your engine and transmission. When it starts to fail, it can cause widespread and confusing issues. Internal circuit board components break down from years of heat cycles and vibration. If you’re experiencing any of the following, a faulty PCM is a very likely cause:
- ✔ Harsh or Erratic Shifting: The transmission may slam into gear, hesitate, or get stuck in one gear (limp mode).
- ✔ Engine Stalling or No-Start: The engine may cut out unexpectedly or refuse to start at all, even with a good battery and starter.
- ✔ Check Engine Light with Multiple Codes: You might see a variety of codes for different sensors, communication errors (U-codes), or internal processor faults.
- ✔ Poor Fuel Economy: Incorrect fuel and timing calculations can cause the engine to run rich or lean, drastically reducing your MPG.
- ✔ Failure to Communicate: A diagnostic scan tool may be unable to connect with the PCM, a sure sign of a major internal fault.
The Solution: A Reliable, Plug-and-Play PCM Programmed for You
Don’t keep throwing parts at the problem. This Powertrain Control Module is the definitive solution to restore your vehicle’s proper operation. The most critical part of the process is the programming, and we handle that for you. When you purchase this module, we use the Vehicle Identification Number (VIN) you provide to flash it with the latest, most stable software updates directly from GM. This isn’t a generic, one-size-fits-all unit; it’s specifically calibrated for your car’s engine, transmission, and factory options.
Why VIN Programming is Essential
- ✔ Guaranteed Compatibility: Ensures the PCM works seamlessly with your specific vehicle systems, including the anti-theft system (VATS/PassKey).
- ✔ Latest GM Updates: We load the newest software, which often includes fixes for factory drivability issues you might not even know you have.
- ✔ Simplified Installation: Because it arrives programmed, you can avoid a costly trip to the dealership for flashing. In most cases, you will only need to perform a simple security relearn procedure which can be done without any special tools.
Guaranteed Fitment for Your Vehicle
This module, service number 9357440, is a direct replacement for several original part numbers. Please verify your part number or match your vehicle from the list below to ensure compatibility. This unit interchanges with the following service numbers: 09356741, 16236757, 9356741, 9357034, and 9366314.
This PCM is confirmed to fit the following vehicles:
- ✔ 1998 Buick: Century (3.1L), LeSabre (3.8L), Park Avenue (3.8L), Regal, Riviera (3.8L), Skylark (3.1L)
- ✔ 1998 Chevrolet: Camaro (3.8L), Lumina, Malibu (3.1L), Monte Carlo, Venture (3.4L)
- ✔ 1998 Oldsmobile: Achieva (3.1L), Cutlass, Eighty Eight, Intrigue, Silhouette
- ✔ 1998 Pontiac: Bonneville, Firebird (3.8L), Grand Am (3.1L), Grand Prix, Trans Sport
- ✔ 1999 Oldsmobile Alero (3.4L): Match ID 16236757, 9356741, 9357034, or 9357440
- ✔ 1999 Pontiac Grand Am (3.4L): Match ID 16236757, 9356741, 9347440, 9357034, or 9366314
- ✔ 1999 Oldsmobile Cutlass: Match ID 16236757
Ordering is simple: After purchase, just send us a message with your vehicle’s 17-digit VIN, and we’ll handle the programming before shipping it directly to you. Get your car back on the road and running right.