Restore Peak Performance to Your GM Truck or Van
If you’re dealing with a frustrating no-start condition, a persistent check engine light, or erratic engine behavior in your 1998 Isuzu Hombre or compatible GM vehicle, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience, I’ve seen firsthand how a faulty PCM can cause a cascade of hard-to-diagnose issues. This isn’t just a part; it’s the brain of your engine, and when it fails, your vehicle’s reliability is compromised. This fully tested, used PCM is the straightforward, cost-effective solution to get your truck back on the road and running smoothly.
The biggest hurdle when replacing a PCM has always been the programming. An unprogrammed module from a junkyard simply won’t work. It needs to be coded specifically to your vehicle’s Vehicle Identification Number (VIN) and its unique options. We eliminate that expensive and time-consuming step for you. Before we ship this module, our experts will flash it with the latest official GM software updates, using the VIN you provide at checkout. This ensures it’s a true plug-and-play solution, restoring factory performance and communication between all your vehicle’s critical systems.
From the Diagnostic Bay
I remember a ’99 Chevy Tahoe that came into the shop with a complaint of intermittent stalling and a random misfire that no one could pin down. The owner had already replaced plugs, wires, and the coil. A scan showed no hard codes, just a history of random misfires. After hooking up a scope, we noticed the injector pulse width was occasionally erratic on several cylinders. This pointed away from a single mechanical part and toward the central controller. We swapped in a VIN-programmed PCM like this one, and the problem vanished instantly. The original PCM’s internal driver for the injectors was failing under heat, a common issue in these units after 20+ years of service. It’s a classic case where shotgunning parts costs more than correctly diagnosing the core electronic fault.
Is Your Truck or Van Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, your engine computer may be at the end of its service life:
- ✔ Check Engine Light is on with communication error codes (like P0601, P0605)
- ✔ Engine cranks but will not start
- ✔ Rough or unstable idle
- ✔ Poor fuel economy
- ✔ Harsh or incorrect shifting from the automatic transmission
- ✔ Failure to pass an emissions test
- ✔ Intermittent stalling for no apparent reason
A Straightforward Guide to Installation
Installing your programmed 1998 Isuzu Hombre PCM is a job most DIYers can handle in under an hour with basic hand tools. Following the correct procedure is key to avoiding any electrical issues.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the PCM: On most of these GM trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect the Connectors: Carefully unclip and remove all wiring harness connectors from the old PCM. These connectors are color-coded and keyed, so you can’t mix them up. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Firmly plug all wiring harness connectors back into the new PCM until they click into place. Reconnect the negative battery terminal.
- Final Step (Important): While the PCM is programmed to your VIN, some vehicles may require a Crankshaft Position System Variation (CASE) relearn procedure to fine-tune its readings for your specific engine and prevent a P1336 code. This can be done with many professional-grade scan tools.
Verified Vehicle Compatibility
This module is a direct replacement for service number 09366810 and is interchangeable with part numbers 09355699, 16266645, 16250279, and 16258815. It fits a wide range of GM vehicles. Please match your part number or verify fitment with your specific make, model, and engine below. This unit fits vehicles that originally came with service ID 09355699.
OLDSMOBILE BRAVADA 98 (4.3L, w/o build date opt ZN4)
CADILLAC ESCALADE 99
CHEVROLET ASTRO 98
CHEVROLET BLAZER S10 98 (w/o build date opt ZN4)
CHEVROLET 1500 PICKUP 98-99 (Gasoline)
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
CHEVROLET EXPRESS 1500 VAN 98-99
CHEVROLET EXPRESS 2500 VAN 98-99 (Gasoline)
CHEVROLET EXPRESS 3500 VAN 98-99 (Gasoline)
CHEVROLET S10 PICKUP 98 (4.3L, w/o build date opt ZN4)
CHEVROLET SUBURBAN 1500 98-99 (Gasoline)
CHEVROLET SUBURBAN 2500 98-99 (Gasoline)
CHEVROLET TAHOE 98-99 (Gasoline)
GMC ENVOY 98 (w/o build date opt ZN4)
GMC JIMMY S15 98 (w/o build date opt ZN4)
GMC 1500 PICKUP 98-99 (Gasoline)
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
GMC SAFARI 98
GMC SAVANA 1500 VAN 98-99
GMC SAVANA 2500 VAN 98-99 (Gasoline)
GMC SAVANA 3500 VAN 98-99 (Gasoline)
GMC SONOMA 98 (4.3L, w/o build date opt ZN4)
GMC YUKON 98-99
Why do I need to provide my VIN?
Your VIN (Vehicle Identification Number) is essential for us to program the PCM correctly. It allows us to load the exact software and calibrations for your vehicle’s engine, transmission, and factory options, ensuring it works perfectly right out of the box.
Is this part difficult to install?
No, installation is straightforward for anyone with basic mechanical skills. It involves disconnecting the battery, unplugging the old module, swapping it with the new one, and reconnecting everything. Please see our installation guide above for the specific steps.
What is a CASE Relearn and will I need to do one?
A CASE (Crankshaft Position System Variation) relearn helps the PCM compensate for tiny variations in the crankshaft reluctor wheel. While not always necessary, performing one with a compatible scan tool is recommended after installation to ensure optimal performance and prevent a P1336 trouble code.
Is this a new part?
No, this is a high-quality, thoroughly tested used part recovered from a salvaged vehicle. Each unit is inspected and verified to be fully functional before being programmed and shipped. This provides a reliable and affordable alternative to a costly new dealer part.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM also controls transmission functions like shift points and line pressure. If your shifting problems are caused by a faulty computer, this part will resolve them. However, it will not fix internal mechanical issues with the transmission itself.