Programmed 1998 S10 Sonoma PCM | VIN-Matched ECU | 09355699

If you’re dealing with frustrating and unpredictable issues in your 1998 Chevy S10, GMC Sonoma, or another compatible GM truck, the Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience under the hood, I’ve seen countless owners chase their tails replacing sensors and spark plugs, only to find the vehicle’s computer was the root cause all along. This isn’t just a replacement part; it’s a definitive solution to restore your truck’s reliability and performance.

This module, corresponding to part numbers 09355699, 16250279, and 09366810, is the central command center for your engine and transmission. Over time, the constant heat cycles and vibrations in the engine bay can degrade internal electronic components, leading to a host of baffling problems. We solve the biggest hurdle of replacement by pre-programming this module specifically to your truck’s Vehicle Identification Number (VIN). This means it arrives at your door ready for installation, loaded with the latest GM software updates, eliminating the need for an expensive trip to the dealership for programming.

Is Your Truck Showing These Symptoms?

A failing PCM can manifest in ways that mimic other component failures. Before you spend more time and money on diagnostics, see if your vehicle is experiencing any of these classic signs of a faulty computer.

• ✔ Persistent Check Engine Light with codes like P0601, P0605 (Internal Module Memory Error) or communication codes (U-codes).
• ✔ Engine stalls unexpectedly, either while driving or at idle.
• ✔ Complete no-start condition where the engine cranks but won’t fire up.
• ✔ Noticeable drop in fuel economy for no apparent reason.
• ✔ Harsh or erratic automatic transmission shifting.
• ✔ Failure to pass an emissions or smog test.
• ✔ Seemingly random misfires that can’t be traced to plugs, wires, or coils.

A Straightforward Guide to Installation

Replacing the 1998 S10 Sonoma PCM is a job most DIYers can handle in their own driveway. With our pre-programmed module, you skip the most complicated step. Just follow this simple process.

1. Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
2. Locate the Module: On most S-10, Blazer, and Jimmy models, the PCM is located in the engine compartment, typically on the passenger-side (RH) fender well, near the firewall. On full-size trucks and vans, it’s often on the driver-side (LH) fender.
3. Disconnect the Harnesses: The PCM has several large multi-pin electrical connectors. Carefully release the locking tabs or levers and pull the connectors straight out from the module. Avoid pulling on the wires themselves.
4. Remove the Old PCM: Unbolt the mounting bracket holding the old module in place. Keep the hardware as you will reuse it for the new module.
5. Install the New Module: Mount your new, VIN-programmed PCM using the original hardware. Ensure it is secure.
6. Reconnect Everything: Firmly plug the electrical harnesses back into the new module until they click into place. Reconnect your negative battery terminal.
7. Perform Security Relearn: Your vehicle may require a simple security relearn procedure (for VATS/Passlock) to sync with the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Instructions are readily available online for your specific model.

Verified Vehicle Compatibility

We guarantee this module is the correct fit for the following vehicles when matching the part ID number. This pre-programmed 1998 S10 Sonoma PCM is a direct-fit solution for a wide range of popular GM models.