Restore Your GM Vehicle’s Performance and Reliability
Is your 1998-1999 Pontiac Grand Am or another compatible GM vehicle suffering from frustrating engine problems? A faulty Powertrain Control Module (PCM) is often the culprit behind issues like stalling, erratic shifting, a persistent Check Engine Light, and poor fuel economy. As a technician with over two decades of experience, I’ve seen firsthand how a failing PCM can disrupt your entire driving experience. This isn’t just an inconvenience; it’s a critical component that needs to function perfectly for your engine’s health and your safety on the road.
This replacement PCM, part number 9356741, is the definitive solution. We take the guesswork and hassle out of the repair by professionally programming the module to your vehicle’s specific Vehicle Identification Number (VIN) before it ships. This means it arrives loaded with the latest GM software updates, ensuring optimal performance and communication with all other vehicle systems. You get a reliable, plug-and-play fix without the expensive trip to a dealership for programming.
A Technician’s Notebook: The Intermittent Stall Case
I remember a 1998 Buick Century that came into my bay with a problem that drove the owner crazy: it would stall randomly at red lights, but only when the engine was fully warmed up. There were no consistent trouble codes, just a history of a P0601 (Internal Control Module Memory Check Sum Error). We checked fuel pressure, ignition components, and sensors—all were fine. After hours of diagnostics, I suspected the PCM. On these older GM units, heat expansion can cause microscopic cracks in the circuit board’s solder joints. When the module got hot, a connection would fail, killing the engine. Once it cooled, it would start right back up. Swapping in a properly programmed PCM like this one solved the issue permanently. It’s a classic failure mode I’ve seen dozens of times.
Common Signs of a Failing PCM
- ✔ Your vehicle fails to start or stalls intermittently.
- ✔ The Check Engine Light is on with codes like P0601, P0602, P0606, or U-series communication codes.
- ✔ You experience a noticeable decrease in fuel efficiency.
- ✔ The engine runs rough, misfires, or hesitates during acceleration.
- ✔ Your automatic transmission shifts harshly, erratically, or not at all.
- ✔ You fail an emissions test due to module-related faults.
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 of these GM vehicles, the PCM is located in the engine bay, often inside the air filter box or mounted to the firewall. On some models like the ’99 Alero/Grand Am, it’s under the left-hand side of the dash. Consult a repair manual for your specific vehicle if you’re unsure.
- ✔ Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- ✔ 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 in place and securely fasten it.
- ✔ Reconnect Everything: Firmly plug the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Perform Security Relearn: Your vehicle’s anti-theft system (Passlock/VATS) will likely need to be synchronized with the new PCM. The typical procedure is: Turn the key to ‘ON’ for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle 3 times. The vehicle should then start.
Verified Vehicle Compatibility
This module is a direct replacement for service numbers 09356741, 16236757, 9357034, 9357440, and 9366314. It is guaranteed to fit the following vehicles, but please match your part number to ensure compatibility:
- Alero: 1999 (3.4L)
- Achieva: 1998 (3.1L)
- Bonneville: 1998
- Camaro: 1998 (3.8L)
- Century: 1998 (3.1L)
- Cutlass: 1998, 1999
- Eighty Eight: 1998
- Firebird: 1998 (3.8L)
- Grand Am: 1998 (3.1L), 1999 (3.4L)
- 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)
Frequently Asked Questions
Do I need to do anything after I buy?
Yes. After your purchase, you must send us your vehicle’s 17-digit VIN. We cannot program and ship your module without it. Please double-check the VIN for accuracy before sending.
Is this part difficult to install?
For someone with basic mechanical skills, this is a straightforward replacement. The most important part is the security relearn procedure, which does not require special tools but must be followed precisely.
Will this fix my Check Engine Light?
If the Check Engine Light is caused by an internal failure of the PCM (like code P0601), then yes, this will resolve the issue. However, you should always ensure other potential problems (sensors, wiring, etc.) have been properly diagnosed first.
What does ‘programmed with the newest updates’ mean?
Over the life of a vehicle, manufacturers like GM release software updates to fix bugs, improve transmission shifting, and enhance engine performance. We flash your module with the latest version available for your specific VIN, ensuring your car runs as well as it possibly can.
How do I find my original part number?
The part number is printed on a sticker on your original PCM. You can match it to the compatible service numbers listed: 09356741, 16236757, 9357034, 9357440, or 9366314.