Restore Peak Performance to Your GM Vehicle
Is your 1998 or 1999 GM vehicle suffering from frustrating, hard-to-diagnose issues? A rough idle, stalling, poor fuel economy, or a persistent Check Engine Light can often be traced back to a single component: a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM controls everything from fuel mixture and ignition timing to transmission shift points. When it starts to fail, the symptoms can be unpredictable and maddening for both car owners and professional mechanics.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and dealership hassle out of the equation. By providing your vehicle’s VIN at checkout, you receive a PCM that is professionally flashed with the latest, most stable GM factory software specific to your car. This ensures optimal performance and can even correct drivability issues that were present in the original factory programming. Stop chasing symptoms and replace the core of your engine management system with a reliable, pre-programmed 1999 Grand Am PCM.
From the Diagnostic Bay: The Ghost in the Machine
I remember a 1999 Oldsmobile Alero with the 3.4L V6 that came into my shop. The owner was at his wit’s end. He’d replaced plugs, wires, and even the fuel pump at another shop, but the car still had an intermittent, violent stalling problem, usually after it warmed up. No consistent codes were stored, just a history of random misfires. After checking all the vitals, I suspected the PCM. On these older GMs, heat stress can cause internal solder joints on the main processor to fail, leading to these exact ghost-like issues. We installed a VIN-programmed PCM, and the problem was gone for good. It’s a classic case where throwing parts at the problem doesn’t work; you have to fix the brain.
Is Your GM Showing These Signs of PCM Failure?
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error), P0602, P0605, or other processor faults.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially when the engine is warm.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Communication errors with your scan tool.
- ✔ Intermittent issues that seem to have no logical cause.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- ✔ Locate the PCM: On most of these vehicles, the PCM is located inside the passenger compartment on the left-hand (driver’s) side, under the dash, or in the engine bay (e.g., inside the air filter housing on vans like the Venture/Silhouette).
- ✔ Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that may need to be gently pried or squeezed. Once disconnected, unbolt the old module from its mounting bracket.
- ✔ Install the New Module: Mount your new, pre-programmed PCM in the same location. Securely reconnect all electrical harnesses. You should hear a ‘click’ as they lock into place.
- ✔ Reconnect Power: Re-attach the negative battery terminal.
- ✔ Perform Security Relearn (If Needed): Turn the key to the ‘ON’ position (don’t start the engine) for 10-15 minutes. You may see the security light flash and then go solid or turn off. Turn the key off for 10 seconds, then start the vehicle. It’s now ready to drive.
Verified Vehicle Compatibility
This module, identified by part number 9357034, is a direct replacement for a wide range of 1998-1999 General Motors vehicles. It is also a compatible replacement for service numbers 09356741, 16236757, 9357440, and 9366314. Please verify your vehicle is on this list:
Achieva 98: 6-191 (3.1L)
Bonneville 98: All Options
Camaro 98: 6-231 (3.8L)
Century 98: 6-191 (3.1L)
Cutlass 98-99: All Options
Eighty Eight 98: All Options
Firebird 98: 6-231 (3.8L)
Grand Am 98: 6-191 (3.1L)
Grand Am 99: (LH center dash), 3.4L, ID 16236757, 9356741, 9366314, 9357034, 9347440
Grand Prix 98: All Options
Intrigue 98: All Options
LeSabre 98: 6-231 (3.8L)
Lumina Car 98: (LH engine compartment)
Malibu 98: 6-191 (3.1L)
Monte Carlo 98: All Options
Park Avenue 98: 6-231 (3.8L)
Regal 98: All Options
Riviera 98: 6-231 (3.8L)
Silhouette 98: (LH engine compartment)
Skylark 98: 6-191 (3.1L)
Trans Sport 98: (LH engine compartment)
Venture 98: 6-207 (3.4L)
By purchasing this 1999 Grand Am PCM, you’re getting a quality part that restores function and reliability, all while saving you the significant cost and time of a dealership visit.
Why do you need my VIN?
Your VIN (Vehicle Identification Number) allows us to flash the module with the exact software and calibrations your vehicle requires from the GM database. This ensures perfect compatibility and plug-and-play installation.
Do I need to take my car to a dealer after installing this?
No. Because the module arrives pre-programmed to your VIN, you do not need to pay for dealership programming. The only potential step is a simple security relearn procedure you can do yourself in your driveway.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM (e.g., codes P0601-P0606), then yes, this will resolve the issue. It’s crucial to diagnose the problem correctly before ordering.
My original part has a different number on it. Will this work?
Yes, this module is a direct replacement for several service numbers, including 09356741, 16236757, 9357440, and 9366314. As long as your vehicle is on the compatibility list, this part will function correctly.
Is this a difficult part for a DIYer to replace?
Not at all. For most DIYers with basic hand tools, this is a straightforward job that can be completed in under an hour. The most important part is safely disconnecting the battery and being gentle with the electrical connectors.