Restore Peak Performance to Your GM Truck or Van
If you’re dealing with a frustrating no-start condition, erratic engine behavior, or a persistent Check Engine Light on your 1998-1999 Chevrolet 1500, the root cause is often a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen firsthand how a faulty PCM can cripple an otherwise solid truck. Heat cycles, vibration, and age take their toll on the internal electronics, leading to issues that can be a nightmare to diagnose. This isn’t just a part; it’s the brain of your vehicle’s engine and transmission, and when it falters, everything else does too.
This is your direct, reliable solution. We’re offering a high-quality replacement 1998-1999 Chevrolet 1500 PCM that eliminates the guesswork and costly trips to the dealership. The biggest hurdle with replacing a PCM is the programming—but we handle that for you. Simply provide your vehicle’s 17-digit VIN during checkout, and our experts will flash the module with the latest GM-certified software specific to your truck. It arrives at your door ready for a straightforward installation, saving you time and hundreds of dollars in dealer programming fees.
Case Study: A Tricky Diagnosis
I remember a ’99 GMC Sierra 5.7L that came into my shop. The owner was at his wit’s end. The truck had an intermittent stall and a hard-start issue, but only when the engine was hot. Two other shops had already replaced the fuel pump and ignition coil with no success. After hooking up my scan tool and monitoring live data, I noticed the injector pulse width was becoming erratic as the engine bay heated up. A classic sign. We pulled the PCM, and sure enough, a thermal-imaging check showed a hot spot on the board. The internal processor was failing under heat stress. We installed a pre-programmed module just like this one, and the truck ran perfectly. It’s a common failure point on these workhorses, and this is the proper fix.
Is Your Truck Showing These Signs of a Failing PCM?
A faulty engine computer can manifest in numerous ways. If you’re experiencing any of the following, a failing PCM is a likely culprit:
- âś” Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- âś” The engine cranks but refuses to start.
- âś” Unexplained stalling, especially after the vehicle has warmed up.
- âś” Rough or unpredictable shifting from the automatic transmission.
- âś” A noticeable drop in fuel economy.
- âś” The engine runs rough, misfires, or idles poorly.
- âś” Communication errors with your scan tool.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks is a job most DIYers can handle in under an hour with basic hand tools. This module is designed for a direct fit.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most 1998-1999 GM full-size trucks and SUVs, the PCM is located in the engine bay on the driver’s side, near the firewall or inner fender.
- Disconnect the Old Unit: Carefully unplug the large multi-pin electrical connectors. They have locking tabs that need to be released. Once unplugged, unbolt the module from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket. Firmly reconnect the electrical connectors, ensuring they click securely into place.
- Reconnect and Test: Reconnect the negative battery terminal. You may need to perform a simple security relearn procedure (often called the “Passlock Relearn”), which typically involves turning the key to the ‘ON’ position for 10 minutes, off for 10 seconds, and repeating this two more times. Your vehicle’s service manual will have the exact steps. Start the engine and verify that it runs smoothly and the check engine light is off.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. Please match one of these numbers from your original module to ensure compatibility. This unit fits a wide range of GM vehicles, including:
GMC 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16250279
GMC 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
SAFARI (GMC) 98-99 Electronic Control Module; (LH front by battery), ID 16250279
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 16258815
YUKON 98-99 Electronic Control Module; (LH engine compartment), ID 16250279
GMC 1500 PICKUP 98 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
GMC 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16250279
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/o build date opt ZN4; ID 16250279
EXPRESS 3500 VAN 98 Electronic Control Module; gasoline, ID 16250279
EXPRESS 2500 VAN 98 Electronic Control Module; gasoline, ID 16250279
ASTRO 99 Electronic Control Module; (LH front by battery), (4.3L), ID 16250279
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 16250279
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16250279
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16250279
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/o extended build date opt ZN4; ID 16258815
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/o build date opt ZN4; ID 16250279
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/o build date opt ZN4; ID 16258815
EXPRESS 1500 VAN 98 Electronic Control Module; ID 16250279
SAVANA 2500 VAN 98 Electronic Control Module; gasoline, ID 16250279
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 16258815
CHEVROLET 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
SAVANA 3500 VAN 98 Electronic Control Module; gasoline, ID 16250279
SUBURBAN 1500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
TAHOE 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
ASTRO 98 Electronic Control Module; (LH front by battery), ID 16250279
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/o build date opt ZN4; ID 16258815
SUBURBAN 2500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/o extended build date opt ZN4; ID 16250279
SAVANA 1500 VAN 98 Electronic Control Module; ID 16250279
CHEVROLET 1500 PICKUP 98 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
CHEVROLET 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 16250279
GMC 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 16250279
Frequently Asked Questions
Frequently Asked Questions
Do I need to take this part to a dealer for programming?
No. We program the module to your vehicle’s specific VIN before we ship it. It arrives ready to be installed, saving you the time and expense of a dealership visit.
What is a VIN and where do I find it?
The VIN is your vehicle’s unique 17-digit identification number. You can typically find it on a small plate on the driver’s side of the dashboard (visible through the windshield) or on the sticker inside the driver’s side door jamb.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like codes P0601, P0605, etc.), then yes, this replacement module will resolve the issue. It’s crucial to ensure the PCM is actually the faulty component.
Is a security relearn procedure required after installation?
Yes, most GM vehicles of this era require a security relearn for the Passlock system to recognize the new PCM. This is a simple procedure you can do yourself with just the ignition key and about 30 minutes of time. Instructions are widely available online or in service manuals.
What part numbers does this module replace?
This unit is a direct, compatible replacement for modules with service numbers 16250279, 09366810, and 09355699. Please verify the number on your current module.