Is Your GM Truck or Van Running Rough, Stalling, or Refusing to Start?
If you’re dealing with a persistent Check Engine Light, erratic engine behavior, or a no-start condition on your 1998-1999 GM vehicle, a failing Powertrain Control Module (PCM) is often the culprit. Over two decades of heat cycles and vibrations can take their toll on these critical components. In my shop, I’ve seen countless GMT400 and Express/Savana platform vehicles with baffling issues that trace back to a faulty PCM. Symptoms can range from harsh shifting and poor fuel economy to a complete shutdown, leaving you stranded.
This isn’t just another part; it’s the solution to get your reliable workhorse back on the road. We are offering a genuine, used OEM Powertrain Control Module, service number 9355699. The key benefit? We professionally program it to your vehicle’s specific Vehicle Identification Number (VIN) before we ship it. This means it arrives ready for a straightforward installation, loaded with the latest GM software updates to ensure optimal performance and efficiency.
From the Shop Floor: A Real-World Diagnosis
“A customer’s ’99 Chevy 2500 came in on a tow truck last week. It would crank but never fire. He had already replaced the fuel pump and ignition coil based on advice from forums, with no luck. After confirming spark and fuel pressure were present, I hooked up a noid light to an injector connector and saw no pulse during cranking. This immediately pointed me to the PCM. The original module’s injector driver circuit had failedโa common issue I’ve diagnosed on over 100 of these specific modules. We installed one of our pre-programmed units, and the truck fired up on the first turn of the key. It’s a textbook case where chasing parts gets expensive, but diagnosing the ‘brain’ provides the real fix.”
Why Choose Our Programmed 1998-1999 GMC 3500 PCM?
This module is the heart of your engine management system. Getting a pre-programmed unit saves you a trip to the dealership, saving you time and the high cost of their programming service. We handle the technical part so you can focus on the simple physical swap.
- โ VIN Programmed: Arrives ready to install, specifically matched to your truck’s options and systems.
- โ Latest GM Software: We flash the module with the most current GM calibrations for improved performance and drivability.
- โ Cost-Effective Solution: A reliable, tested used OEM part that provides immense value over a new, expensive dealer component.
- โ Broad Compatibility: Directly replaces multiple part numbers, including 16266645, 16250279, 16258815, and 09366810.
- โ Fixes Common Issues: Solves problems like random stalling, no-start, false sensor codes, and poor transmission shifting.
Easy Installation: Get Back on the Road Fast
Replacing the PCM on these GM trucks and vans is a job most DIYers can handle in under 30 minutes with basic tools. It’s typically located in the engine bay on the driver’s side.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: Find the existing module in the engine compartment. It will have several large multi-pin connectors.
- Disconnect Connectors: Carefully unclip and remove all electrical connectors. Inspect them for any corrosion or bent pins. A quick spray with electronics cleaner is a great preventative measure.
- Remove Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install New Module: Mount your new, pre-programmed PCM, reconnect all electrical harnesses securely, and finally, reconnect the negative battery terminal.
- Final Step: While the module is plug-and-play, some vehicles may require a Crankshaft Variation Relearn (often called a CASE relearn) to be performed with a capable scan tool for optimal performance and to clear a potential P1336 code. This is a simple procedure for any professional mechanic.
Please provide your 17-digit VIN in the notes at checkout or send us a message after your purchase so we can program the module for your specific vehicle.