Restore Your GM Truck’s Performance and Reliability
Is your 1998 Chevrolet Blazer S10 or GMC Jimmy S15 acting up? Experiencing frustrating issues like stalling, erratic shifting, a persistent Check Engine Light, or a complete no-start condition? The Powertrain Control Module (PCM), the electronic brain of your vehicle, is often the culprit. When it fails, it can cause a host of problems that sideline even the most dependable trucks. This isn’t just an inconvenience; it’s a critical failure that affects safety and driveability. Don’t let a faulty computer keep you off the road or drain your wallet at the dealership.
We offer a dependable, cost-effective solution: a thoroughly tested, used OEM Powertrain Control Module. The best part? We handle the programming for you. Simply provide your vehicle’s VIN during checkout, and our technicians will flash this PCM with the latest official GM software specific to your truck. It arrives at your door ready for a straightforward installation, eliminating the need for expensive scan tools or a trip to the dealer for programming. This is the most direct path to getting your vehicle running right again.
A Technician’s Notebook
I remember a ’98 GMC Jimmy S15 that came into the shop with a ghost of a problem. The owner said it would randomly refuse to start, but only after it was warm. Other times, it would shift hard from first to second. There were no consistent codes, just a general U-code for lost communication that would pop up now and then. We checked all the usual suspects—grounds, battery connections, ignition switch. Everything seemed fine. On a hunch, I tapped the PCM casing with a screwdriver handle while the engine was idling, and it immediately stalled. That confirmed it: an internal failure in the module was causing these intermittent headaches. A pre-programmed replacement like this one had the truck running reliably in under an hour.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re noticing any of the following, it’s a strong indicator that your engine computer needs attention:
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Other modules (like the ABS or BCM) setting ‘Lost Communication with ECM’ codes.
A Straightforward Guide to Installation
Replacing the PCM in these GM trucks is a job most DIYers can handle with basic tools. Our pre-programmed module makes it even easier. Follow these general steps to get back on the road:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the PCM: On the 1998 Blazer/Jimmy, the PCM is typically located in the engine compartment on the passenger (RH) side, near the firewall or inner fender. For other models like Express/Savana vans, it may be in the rear engine compartment.
- Disconnect the Connectors: The PCM has several large multi-pin electrical connectors. Carefully release the locking tabs or levers on each connector and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are usually a few 7mm or 10mm bolts holding it in place.
- Install the New Module: Seat your new, VIN-programmed PCM into the mounting bracket and secure it with the bolts.
- Reconnect Everything: Firmly plug the electrical connectors back into the new PCM, ensuring they click and lock into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In many cases, you will need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this sequence three times. This allows the vehicle’s anti-theft system to recognize the new PCM. Your engine should now start and run correctly.
Verified Vehicle Compatibility
This module is a direct replacement for service number 09366810 and interchanges with several other part numbers, including 09355699, 16266645, 16250279, and 16258815. It is confirmed to fit a wide range of 1998-1999 GM trucks and vans. Please verify your vehicle is on this list and that your original module carries one of the compatible part numbers.
CHEVROLET ASTRO 98 (LH front by battery), ID 9355699
GMC SAFARI 98 (LH front by battery), ID 9355699
OLDSMOBILE BRAVADA 98 (6-262, 4.3L), w/o build date opt ZN4; ID 9355699
GMC ENVOY 98 (RH front engine compartment), w/o build date opt ZN4; ID 9355699
CHEVROLET S10/S15/SONOMA 98 (6-262, 4.3L), w/o build date opt ZN4; ID 9355699
ISUZU HOMBRE 98 4.3L (6 cyl), w/o extended build date opt ZN4; ID 9355699
CHEVROLET/GMC 1500/2500/3500 PICKUPS 98-99 (Gasoline, LH engine comp), ID 9355699
CHEVROLET TAHOE 98-99 (Gasoline, LH front engine comp), ID 9355699
GMC YUKON 98-99 (LH engine comp), ID 9355699
CADILLAC ESCALADE 99 (LH front engine comp), ID 9355699
CHEVROLET SUBURBAN 1500/2500 98-99 (Gasoline, LH front engine comp), ID 9355699
CHEVROLET EXPRESS VANS 1500/2500/3500 98-99 (Gasoline), ID 9355699
GMC SAVANA VANS 1500/2500/3500 98-99 (Gasoline), ID 9355699
Frequently Asked Questions
Do I need to do any programming myself?
No. This PCM comes fully programmed to your vehicle’s VIN with the latest GM software updates. It is ready for installation right out of the box, though a simple security relearn procedure may be required.
What information do you need from me?
After you complete your purchase, you must provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We cannot program and ship the module without it.
Is this a new part?
No, this is a genuine, used OEM part that has been sourced from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional before being programmed and shipped.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like code P0601), then yes, this part will resolve the issue. However, if the light is on due to a faulty sensor or other component, you will still need to fix that underlying problem.
What is the security relearn procedure?
It’s a simple process that syncs the new PCM with your vehicle’s anti-theft system. It typically involves cycling the ignition key on and off in a specific sequence. Instructions are widely available online for your specific model, or you can contact our support team.