Restore Peak Performance to Your Truck or Van
Is your truck suffering from a persistent check engine light, erratic shifting, or a frustrating no-start condition? The Powertrain Control Module (PCM), often called the engine’s brain, is the central command for all critical engine and transmission functions. When it starts to fail, it can cause a cascade of confusing and costly problems. I’ve seen it hundreds of time in my 20+ years in the shop: a perfectly good engine held back by a faulty computer. This isn’t just an inconvenience; it affects fuel economy, emissions, and overall vehicle reliability.
This is a dependable, tested, and pre-programmed replacement PCM for a wide range of GM vehicles, including the 1998 Isuzu Hombre PCM. We take the guesswork and high dealership costs out of the equation. Each module is sourced from a salvaged vehicle and meticulously tested for full functionality. The real value is in our service: before we ship it, we flash the unit with the latest GM software updates and program it specifically to your vehicle’s Vehicle Identification Number (VIN). This ensures it’s a true plug-and-play solution, ready for installation right out of the box.
A Technician’s Notebook: The Ghost in the Machine
A few months back, a 1998 GMC Jimmy S15 was towed into the bay. The owner was at his wit’s end. It had an intermittent no-start, and when it did run, the transmission would shift hard from first to second. He’d already replaced the ignition switch and a transmission solenoid to no avail. The scanner showed a few generic communication codes but nothing concrete. After checking the main power and ground circuits to the PCM, I noticed the 5-volt reference signal to the throttle position sensor was fluctuating slightly. On a hunch, I connected a spare PCM we had on the shelf. The truck fired up instantly, the voltage signal stabilized, and it shifted perfectly on the test drive. The original PCM had internal circuit board failure, causing unpredictable issues. This pre-programmed module is the exact fix for that kind of hard-to-diagnose problem.
Is Your Truck’s Brain Failing? Watch for These Signs
A failing PCM can manifest in many ways. If you’re experiencing any of the following, your engine computer could be the culprit:
- ✔ Check Engine Light is on with codes like P0601, P0605, or P0606 (Internal Control Module errors).
- ✔ Unexplained drop in fuel efficiency.
- ✔ Engine cranks but refuses to start.
- ✔ Rough or unstable idling.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stalling for no apparent reason.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Your PCM Swap
Replacing the PCM on these GM trucks and vans is a job most DIYers can handle with basic tools. While the exact location varies slightly by model (see fitment list), the process is generally the same. Getting your 1998 Isuzu Hombre PCM installed is simple.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: It’s typically found in the engine bay, often on the driver’s side fender, near the battery, or on the firewall.
- Disconnect the Wiring: Carefully unplug the wiring harness connectors. These usually have a locking tab or lever that needs to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are typically two or three bolts holding it in place.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click securely in place. Reconnect the negative battery terminal.
- Security Relearn (If Necessary): In most cases, the vehicle will start and run. However, some models may require a simple security relearn procedure (often called a CASE relearn) which can be done with a capable scan tool to sync the new PCM with the crankshaft position sensor for optimal performance.
Verified Compatibility for Your GM Truck or Van
This module is a direct replacement for service number 16258815 and other interchangeable part numbers like 09355699, 16266645, and 9366810. Please verify your original part number or use the compatibility list below. This part is guaranteed to fit the following vehicles with the specified options:
ASTRO 98 (LH front by battery)
BLAZER S10/JIMMY S15 98 (w/o build date opt ZN4)
BRAVADA 98 (4.3L, w/o build date opt ZN4)
ENVOY 98 (w/o build date opt ZN4)
S10/S15/SONOMA 98 (4.3L, w/o build date opt ZN4)
CHEVROLET 1500 PICKUP 98-99 (Gasoline)
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
GMC 1500 PICKUP 98-99 (Gasoline)
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
SUBURBAN 1500/2500 98-99 (Gasoline)
TAHOE/YUKON 98-99 (Gasoline)
ESCALADE 99
EXPRESS 1500/2500/3500 VAN 98-99 (Gasoline)
SAVANA 1500/2500/3500 VAN 98-99 (Gasoline)
SAFARI (GMC) 98 (LH front by battery)
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after I buy this PCM?
Yes. After you complete your purchase, you MUST send us your vehicle’s 17-digit VIN. We cannot program and ship the module without it.
Is this a new part?
No, this is a high-quality, fully tested used part sourced from a salvaged vehicle. This allows us to provide a reliable and affordable solution.
What does ‘VIN Programmed’ mean?
It means we load your vehicle’s specific factory software and settings onto the PCM using your VIN. This makes it compatible with your truck’s engine, transmission, and options, ensuring a simple installation.
Will I need a mechanic to install this?
For most DIYers with basic tools, this is a straightforward replacement. However, some vehicles may require a Crankshaft Variation Relearn (CASE Relearn) procedure with a scan tool to clear certain trouble codes and ensure perfect engine timing calibration.
What if I have a different part number on my original module?
This module replaces several part numbers, including 09355699, 16266645, 9355699, 16250279, and 9366810. As long as your part number is on our list, this module will work for you.