Is Your GM Truck Running Out of Ideas?
If your 1998 or 1999 GMC Yukon, Chevy Tahoe, or Suburban is suddenly acting possessedโstalling at lights, shifting erratically, or refusing to start altogetherโthe problem often points directly to a failing Powertrain Control Module (PCM). Over the years, I’ve seen hundreds of these GMT400-platform trucks roll into my bay with symptoms that leave owners scratching their heads. The Check Engine Light is on, but the codes are confusing, pointing to multiple sensors at once. This isn’t a dozen failing parts; it’s one failing computer.
From the Shop Floor: A Real-World Diagnosis
“A customer’s ’99 Suburban came in last week with these exact symptoms. It had a persistent random misfire code (P0300) and an intermittent no-start that he couldn’t pin down. He’d already replaced the plugs, wires, cap, and rotor. After checking fuel pressure and finding no vacuum leaks, we scoped the injector signals right at the PCM connector. Sure enough, the driver for cylinder 3 was dropping out randomly. A new set of plugs won’t fix a faulty computer circuit. This programmed PCM resolved all his issues in one afternoon.”
The Direct Solution: A Programmed, Ready-to-Install PCM
Don’t just buy another used computer and hope for the best. This is a tested, genuine GM PCM that we program specifically for your vehicle using your VIN. This critical step ensures that all the correct parameters for your engine, transmission, and options are loaded correctly. We also flash it with the latest GM software updates, which often correct factory bugs related to idle stability and transmission performance that were discovered after your truck left the showroom.
Common Symptoms of a Failing 1998-1999 Yukon PCM:
- โ Complete no-start or intermittent starting condition
- โ Harsh, delayed, or unpredictable transmission shifting
- โ A persistent Check Engine Light with communication codes (U-codes) or multiple, unrelated sensor codes
- โ Noticeable drop in fuel economy
- โ Engine stalling or running rough for no apparent reason
- โ Failure to pass an emissions test
Plug-and-Play Installation: No Dealer Visit Required
Replacing the PCM on these trucks is a straightforward job you can do with basic hand tools. Because we program it to your VIN before shipping, you can skip the expensive trip to the dealership for programming. You may need to perform a simple security relearn procedure, which takes about 30 minutes and involves only your ignition key.
- Safety First: Disconnect the negative battery terminal and wait 10 minutes.
- Locate the PCM: On most of these trucks and vans, it’s located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. Note their colors or positions. Then, unbolt the PCM from its mounting bracket.
- Install the New PCM: Bolt your new, programmed PCM into place. Reconnect the wiring harnesses, ensuring they click securely into place.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Security Relearn (if needed): Turn the key to the ‘ON’ position (don’t start) for 10-15 minutes. The ‘Security’ light should turn off. Turn the key off for 10 seconds, then start the engine. Your truck is ready to go.
Guaranteed Compatibility
This module, service number 09366810, is a direct replacement for several part numbers, including 09355699, 16266645, and 16250279. It fits a wide range of GM vehicles from 1998-1999, including the Chevy/GMC C/K 1500, 2500, 3500 pickups, Suburban, Tahoe, Yukon, Express, Savana, and more. After your purchase, simply provide us with your VIN, and we’ll handle the rest, ensuring a perfect match.