Is your 1999 Cadillac Escalade or GM truck acting up? Dealing with a persistent Check Engine Light, rough idling, stalling, or unpredictable shifting can be incredibly frustrating. As a mechanic with over two decades of diagnostic experience, I’ve seen these symptoms countless times. More often than not, the root cause is a failing Powertrain Control Module (PCM), the computer that serves as your vehicle’s brain.
Don’t let a faulty computer keep your reliable truck off the road. This is a direct-fit replacement PCM, service number 16250279, that solves those issues for good. The best part? We take the guesswork and extra cost out of the repair. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and we will program the module with the very latest GM factory software before it even leaves our facility. It arrives at your door ready for a straightforward installation, saving you a trip to the dealership and their expensive programming fees.
Is Your GM Truck or SUV Showing These Signs?
A failing PCM can cause a wide range of confusing electrical and performance problems. If you’re experiencing any of the following, a faulty module is the likely culprit:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough, inconsistent idling.
- ✔ Noticeably poor fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with your scan tool.
A Technician’s Notebook
I remember a 1998 GMC K2500 that came into the shop with a ghost of a problem. The owner said it would randomly stall at red lights, but never threw a consistent code. We checked fuel pressure, ignition components, and sensors—all were fine. After hours of diagnostics, we hooked up a scope to the PCM’s power and ground circuits. We saw a momentary voltage drop inside the module itself right before it would stall. The internal processor was failing under load. We swapped in a VIN-programmed 1999 Escalade Powertrain Control Module (which shares the same architecture) and the problem vanished instantly. The customer went from facing hundreds in diagnostic fees to a simple, effective fix.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is one of the easier DIY jobs. With basic hand tools, you can get it done in under 30 minutes.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these vehicles, you’ll find the PCM in the engine bay, typically on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old module. They have locking tabs, so be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into the bracket.
- Reconnect Everything: Firmly plug the electrical harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Final Step: In some cases, a security relearn procedure may be necessary. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle’s service manual will have the specific steps if required.
Verified Vehicle Compatibility
This module, identified by part number 16250279, is a direct replacement for service numbers 09366810 and 09355699. It is guaranteed to fit the following vehicles:
– 1999 Escalade (LH front engine compartment)
Chevrolet:
– 1998-1999 C/K 1500, 2500, 3500 Pickup (Gasoline)
– 1998-1999 Suburban 1500, 2500 (Gasoline)
– 1998-1999 Tahoe (Gasoline)
– 1998-1999 Express 1500, 2500, 3500 Van (Gasoline)
– 1998-1999 Astro Van (4.3L)
– 1998 S10 Blazer (4.3L, w/o build date opt ZN4)
– 1998 S10 Pickup (4.3L, w/o build date opt ZN4)
GMC:
– 1998-1999 C/K 1500, 2500, 3500 Pickup (Gasoline)
– 1998-1999 Yukon (Gasoline)
– 1998-1999 Savana 1500, 2500, 3500 Van (Gasoline)
– 1998-1999 Safari Van (4.3L)
– 1998 Jimmy S15 (4.3L, w/o build date opt ZN4)
– 1998 Sonoma S15 (4.3L, w/o build date opt ZN4)
– 1998 Envoy (w/o build date opt ZN4)
Oldsmobile:
– 1998 Bravada (4.3L, w/o build date opt ZN4)
Isuzu:
– 1998 Hombre (4.3L, w/o extended build date opt ZN4)
Frequently Asked Questions
What exactly does a Powertrain Control Module do?
The PCM is the central computer that controls all aspects of your engine and transmission. It manages fuel injection, ignition timing, emission systems, and shift points to ensure the vehicle runs efficiently and smoothly.
Is this module really plug-and-play?
Yes. Because we program it with your vehicle’s specific VIN before shipping, it is ready to be installed without any additional programming or trips to a mechanic. In rare cases, a simple security relearn procedure may be needed, which you can do yourself.
Where do I find my vehicle’s VIN?
Your 17-digit VIN can be found on your vehicle’s registration, your insurance card, or on a small plate on the driver’s side of the dashboard, visible through the windshield.
What happens if I don’t provide my VIN?
We cannot ship the module without a VIN. The programming is essential for the part to function correctly with your vehicle’s specific systems, engine, and transmission. This step ensures compatibility and proper operation.
How can I be certain my old PCM has failed?
While the symptoms listed above are strong indicators, the best way to be 100% sure is to have a professional mechanic perform a diagnostic check. Common failure codes like P0601 through P0606 are a definitive sign of an internal PCM fault.