Get Your Workhorse Van Back on the Job
Is your 1998-1999 Chevrolet Express 3500 Van letting you down? If you’re dealing with frustrating issues like intermittent stalling, a persistent check engine light, or a no-start condition that leaves you stranded, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your engine and transmission, its health is critical. This isn’t just a replacement part; it’s a reliable, cost-effective solution to restore your van’s performance and dependability. We take a quality, inspected used OEM module and program it specifically for your vehicle using your VIN, ensuring it arrives ready for a straightforward installation.
A Technician’s Notebook
I remember a fleet customer with a ’99 Express 3500 cargo van that was becoming a real headache. The driver reported it would randomly die at stoplights, then refuse to restart for 10-15 minutes. They’d already replaced the fuel pump and ignition control module with no luck. When it got to my bay, I pulled a P0601 (Internal Control Module Memory Check Sum Error) code. This code is a direct indictment of the PCM itself. Instead of sending them to the dealer for a new, expensive unit and programming fees, we sourced a tested used module like this one. We programmed it to their VIN, they installed it in their lot, and the van was back in reliable service the next day. This is a classic failure on these workhorse GM vehicles, and a pre-programmed module is the most efficient fix.
Is Your Van Showing These Symptoms?
A failing PCM can cause a wide range of problems. If you’re experiencing any of the following, this module is the likely solution.
- ✔ Check Engine Light is on with codes like P0601, P0602, or P0605.
- ✔ Engine stalls unexpectedly or for no apparent reason.
- ✔ Vehicle won’t start, but the battery and starter are good.
- ✔ Noticeable decrease in fuel economy.
- ✔ Transmission shifts harshly, erratically, or at the wrong times.
- ✔ Failure to pass an emissions or smog test.
A Straightforward Guide to Installation
One of the biggest benefits of our service is that this 1998-1999 Express 3500 PCM arrives ready to install, with no dealer programming required. While a security relearn procedure may be necessary, the physical swap is simple.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: On most Express/Savana vans, the PCM is located in the engine compartment, on the left (driver’s) side, often near the battery or air filter box.
- Disconnect the Connectors: Carefully unlatch and remove the electrical harness connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your pre-programmed PCM onto the bracket and securely reconnect the electrical harnesses. Ensure they click into place.
- Reconnect Power: Reattach the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, you’ll need to perform a security relearn. A common method is the 30-minute procedure: Turn the key to the ‘ON’ position for 10 minutes, turn it ‘OFF’ for 10 seconds, and repeat this cycle two more times. Your vehicle should then start and run normally.
Verified Vehicle Compatibility
This module, identified by part number 16266645 or service number 09355699, fits a wide range of GM trucks and vans. Please verify your original part number or consult the list below. Providing your VIN at checkout is the best way to guarantee perfect compatibility.
CHEVROLET 2500 PICKUP 98-99 (Gasoline, ID 9355699)
CHEVROLET 3500 PICKUP 98-99 (Gasoline, ID 9355699)
EXPRESS 1500 VAN 98-99 (ID 9355699)
EXPRESS 2500 VAN 98-99 (Gasoline, ID 9355699)
EXPRESS 3500 VAN 98-99 (Gasoline, ID 9355699)
GMC 1500 PICKUP 98-99 (Gasoline, ID 9355699)
GMC 2500 PICKUP 98-99 (Gasoline, ID 9355699)
GMC 3500 PICKUP 98-99 (Gasoline, ID 9355699)
SAVANA 1500 VAN 98-99 (ID 9355699)
SAVANA 2500 VAN 98-99 (Gasoline, ID 9355699)
SAVANA 3500 VAN 98-99 (Gasoline, ID 9355699)
ASTRO 98 (ID 9355699)
BLAZER S10/JIMMY S15 98 (w/o build date opt ZN4; ID 9355699)
BRAVADA 98 (w/o build date opt ZN4; ID 9355699)
CADILLAC ESCALADE 99 (ID 9355699)
ENVOY 98 (w/o build date opt ZN4; ID 9355699)
ISUZU HOMBRE 98 (4.3L, w/o extended build date opt ZN4; ID 9355699)
S10/S15/SONOMA 98 (4.3L, w/o build date opt ZN4; ID 9355699)
SAFARI (GMC) 98 (ID 9355699)
SUBURBAN 1500 98-99 (Gasoline, ID 9355699)
SUBURBAN 2500 98-99 (Gasoline, ID 9355699)
TAHOE 98-99 (Gasoline, ID 9355699)
YUKON 98-99 (ID 9355699)
This module is a direct replacement for part numbers: 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, 9366810.
Frequently Asked Questions
1998-1999 Express 3500 PCM
What if this doesn’t fix my problem?
While this fixes the listed symptoms in most cases, we always recommend proper diagnostics. If the module does not solve your issue, you may have another underlying problem. Please contact us to discuss our return policy.