Get Your Workhorse Van Running Right Again
Is your 1998 or 1999 GMC Savana 2500 van giving you headaches? Unexplained stalling, a persistent check engine light, or rough, unpredictable engine performance can bring your work to a grinding halt. As the central command center for your engine, a failing Powertrain Control Module (PCM) is often the culprit. This isn’t just an inconvenience; it affects your fuel economy, reliability, and safety. This tested, OEM engine computer is the dependable, straightforward solution to get your van back on the road and working as hard as you do.
We take the biggest hassle out of the repair process. Forget expensive dealership visits and towing fees. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) after your purchase, and our technicians will program this PCM with the latest official GM software specific to your Savana. It arrives at your door ready for installation, making the repair process as simple as possible.
Case Study: A Tricky Diagnosis
I remember a ’99 Chevy Express 2500 that came into my shop—same platform as your Savana. The owner was frustrated; he’d replaced the fuel pump and ignition coil, but it still had an intermittent no-start condition, especially on hot days. There were no consistent trouble codes, just a general communication error that would pop up and disappear. After checking all the wiring for the third time, we swapped in a known-good PCM. The van fired up instantly and ran perfectly for a week of testing. The original PCM’s internal processor was failing under heat, a classic issue with these modules after 20+ years of service. This replacement part solves that exact kind of hard-to-diagnose electrical gremlin.
Common Signs of a Failing GM PCM
If you’re experiencing any of the following, a faulty engine computer could be the root cause. A failing PCM can cause a wide array of problems that might otherwise seem unrelated.
- ✔ Your vehicle will not start or is very difficult to start.
- ✔ The check engine light is on, often with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A sudden, unexplained drop in fuel efficiency.
- ✔ The engine stalls, stumbles, or misfires for no apparent reason.
- ✔ You have failed an emissions test.
A Straightforward Guide to Installation
Replacing the PCM on your Savana or Express van is a job most DIYers can handle with basic tools. Because we program it beforehand, you won’t need any special scan tools for setup.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On these vans, the PCM is typically found in the engine compartment on the driver’s side, near the auxiliary battery tray or firewall.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few 7mm or 10mm bolts.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely re-connect the wiring harnesses. You should hear a ‘click’ as they lock into place.
- Reconnect Battery: Re-attach the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes.
Will This Fit My Vehicle?
This PCM is a guaranteed fit for a wide range of 1998-1999 General Motors trucks and vans that use service ID 9355699. While this listing is for the 1998-1999 Savana 2500 PCM, it is also the correct part for many other models. It directly replaces part numbers 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. Key compatible models include:
- ✔ Chevrolet Express & GMC Savana Vans (1500, 2500, 3500)
- ✔ Chevrolet & GMC Pickups (1500, 2500, 3500)
- ✔ Chevrolet Tahoe & GMC Yukon
- ✔ Chevrolet Suburban & GMC Suburban
- ✔ Cadillac Escalade
- ✔ Chevrolet Astro & GMC Safari
- ✔ Chevrolet S10, GMC Sonoma, Oldsmobile Bravada, Isuzu Hombre
Please verify your original part number or contact us with your VIN if you are unsure about compatibility.
Frequently Asked Questions
Why do you need my VIN?
Your VIN is essential for us to program the PCM with the correct software for your vehicle’s specific engine, transmission, and options. This ensures it works perfectly right out of the box.
Is this part difficult to install?
No. For most DIYers with basic hand tools, this is a very manageable job. Since the unit comes pre-programmed, there are no complex computer procedures required after installation. Just plug it in.
What does ‘used’ mean for this part?
This is a genuine OEM part that was recovered from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional before being programmed with fresh GM software and shipped to you.
Will I need to do anything else after installation?
In most cases, no. However, some GM vehicles of this era require a Case-to-Crankshaft Variation Relearn procedure (CASE Relearn) to be performed with a scan tool for optimal performance and to clear a potential P1336 code. Many vehicles will run fine without it, but we recommend it for a complete repair.
What if I order the wrong part?
We strongly encourage you to match your original part number to the ones listed. Providing your VIN for programming helps us double-check compatibility and prevent errors before we ship.