Is Your GM Truck or Van Running Rough?
If your 1998-1999 Chevrolet, GMC, or Cadillac is experiencing puzzling issues like stalling, erratic shifting, poor fuel economy, or a persistent check engine light, the problem may lie with its most critical component: the Powertrain Control Module (PCM). As the central computer, the PCM manages everything from fuel injection and spark timing to transmission shift points and emissions controls. When it fails, the symptoms can be frustrating and difficult to diagnose, often mimicking other part failures.
From the Diagnostic Bay
We once had a 1998 Chevy C1500 in the shop that was driving its owner crazy. He had replaced the throttle position sensor, the idle air control valve, and even the fuel pump, but it still had a rough, hunting idle and would stall at stoplights. After hooking up our scanner, we noticed the data stream from the PCM was erratic. The computer itself was failing internally, sending incorrect commands to the very parts he had just replaced. We installed a VIN-programmed PCM just like this one, performed the quick security relearn, and the truck ran like it just rolled off the factory floor. It’s a classic case of treating the cause, not just the symptoms.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or hesitating unexpectedly.
- ✔ Rough or inconsistent idling.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Failure to pass state emissions testing.
The Direct-Fit, Programmed Solution for Your Vehicle
Don’t waste time and money on parts you don’t need. This genuine, used OEM Powertrain Control Module is the reliable and cost-effective solution to restore your vehicle’s performance and dependability. We take the guesswork out of the repair by pre-programming the module specifically for your vehicle using your unique Vehicle Identification Number (VIN). This ensures that the computer has the correct software and calibrations for your engine, transmission, and specific options, straight from the GM database. It’s a true plug-and-play repair.
Why a VIN-Programmed 1998 S10 PCM is Essential
For vehicles of this era, simply swapping a computer from another truck won’t work. The PCM is tied to the vehicle’s security system (PassLock/VATS) and specific hardware. Our programming service handles this critical step for you. By flashing the unit with the latest GM updates and your VIN, we ensure it communicates perfectly with the other modules in your vehicle. Upon installation, you may only need to perform a simple security relearn procedure, which typically takes about 10-15 minutes and requires no special tools.
Guaranteed Compatibility and Fitment
This module, identified by part numbers 09366810 and 09355699, is a direct replacement for a wide range of 1998 and 1999 GM vehicles. Please verify your part number and check the comprehensive list below to confirm fitment. If you are unsure, contact us with your VIN, and we’ll be happy to verify compatibility for you.
This module is a confirmed fit for the following vehicles with service ID 09355699:
- Astro / Safari (GMC): 1998
- Blazer S10 / Jimmy S15: 1998 (w/o build date opt ZN4)
- Bravada: 1998 (w/o build date opt ZN4)
- Cadillac Escalade: 1999
- Chevrolet 1500/2500/3500 Pickup: 1998-1999 (Gasoline)
- Envoy: 1998 (w/o build date opt ZN4)
- Express 1500/2500/3500 Van: 1998-1999 (Gasoline)
- GMC 1500/2500/3500 Pickup: 1998-1999 (Gasoline)
- Isuzu Hombre: 1998 (4.3L, w/o extended build date opt ZN4)
- S10 / S15 / Sonoma: 1998 (4.3L, w/o build date opt ZN4)
- Savana 1500/2500/3500 Van: 1998-1999 (Gasoline)
- Suburban 1500/2500: 1998-1999 (Gasoline)
- Tahoe / Yukon: 1998-1999 (Gasoline)
Frequently Asked Questions
Do I need to program this module?
No. We program the module to your vehicle’s VIN before shipping. This makes the installation process as simple as possible. You will not need to take it to a dealer for programming.
Is this a new part?
This is a high-quality, tested, and fully functional used OEM part sourced from a salvaged vehicle. This ensures OEM-level reliability and a perfect fit without the high cost of a new module.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.
What do I need to do after installing the PCM?
In most cases, you will need to perform a simple security relearn procedure. This usually involves turning the key to the ‘ON’ position for 10-12 minutes, then off, and repeating two more times. This allows the PCM to sync with your vehicle’s anti-theft system. Specific instructions can be easily found for your model.
How can I be sure my old PCM is the problem?
While the symptoms listed are strong indicators of a failing PCM, we always recommend a thorough diagnosis by a qualified mechanic. This can help rule out other potential issues like bad sensors, wiring problems, or fuel delivery issues before replacing the computer.