Restore Peak Performance to Your GM Truck or SUV
Is your 1998-1999 Chevy Tahoe, Suburban, or GMC Yukon acting up? If you’re dealing with a persistent Check Engine Light, rough idling, stalling, or poor fuel mileage, the problem often points directly to a failing Powertrain Control Module (PCM). As the ‘brain’ of your vehicle, a faulty PCM can cause a host of frustrating and hard-to-diagnose issues. This isn’t just an annoyance; it affects your vehicle’s reliability, fuel efficiency, and safety. I’ve seen countless trucks in my bay with these exact symptoms, and a failing computer was the culprit more than half the time.
This is a reliable, tested, and ready-to-install replacement PCM, part number 9355699. We take the biggest hassle out of the repair process: programming. Simply provide us with your vehicle’s VIN at checkout, and we will flash this module with the latest GM-certified software specifically for your truck. This means it arrives at your door ready for a straightforward installation, saving you a costly trip to the dealership and their programming fees.
From the Diagnostic Bay: The Case of the Intermittent Stall
A customer brought in his ’99 Suburban 1500. It would run fine for days, then suddenly stall at a stoplight and refuse to restart for 10-15 minutes. No consistent codes were stored, just a random misfire code now and then. We checked fuel pressure, ignition components, and sensors—all were fine. After hours of diagnostics, I noticed that wiggling the PCM connectors would sometimes cause the engine to stumble. On a hunch, we swapped in a known-good PCM. The problem vanished instantly. The original PCM had an internal circuit board failure that was only apparent when it got hot. This replacement 1998-1999 Tahoe PCM is the exact fix for these hard-to-trace electronic gremlins.
Is Your Truck’s Brain Failing? Common Symptoms
If you’re experiencing any of the following, a failing PCM is a likely cause. A faulty module can trigger diagnostic trouble codes (DTCs), and one of the most common for internal failure is P0601 (Internal Control Module Memory Check Sum Error).
- ✔ Check Engine Light is on or flashes intermittently
- ✔ Vehicle will not start or is difficult to start
- ✔ Stalling or rough, erratic idling
- ✔ Noticeable decrease in fuel economy
- ✔ Harsh or incorrect automatic transmission shifting
- ✔ Failure to pass an emissions inspection
- ✔ Communication errors with diagnostic scan tools
A Mechanic’s Guide to a Smooth PCM Swap
Installing your pre-programmed 1998-1999 Tahoe PCM is a job most DIYers can handle in under an hour with basic hand tools. Following these steps ensures a smooth process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for capacitors to discharge.
- 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 the electrical wiring harnesses. These connectors have locking tabs; be gentle to avoid breaking them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in by a few bolts (commonly 10mm).
- Install the New Module: Mount your new PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: Your vehicle may require a simple security relearn procedure to recognize the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for the specific procedure for your model.
Verified Fitment for Your GM Truck or Van
This module, identified by part number 9355699, is a direct replacement for a wide range of GM vehicles. Please match your original part number or use the compatibility list below to confirm fitment. This unit is compatible with service numbers: 09355699, 16266645, 16250279, 16258815, 09366810, 9366810.
CHEVROLET 2500 PICKUP 98-99 (Gasoline, LH engine compartment)
CHEVROLET 3500 PICKUP 98-99 (Gasoline, LH engine compartment)
TAHOE/YUKON 98-99 (Gasoline, LH engine compartment)
SUBURBAN 1500/2500 98-99 (Gasoline, LH front engine compartment)
ESCALADE 99 (LH front engine compartment)
EXPRESS/SAVANA VAN 1500/2500/3500 98-99 (Gasoline)
ASTRO/SAFARI VAN 98 (LH front by battery)
BLAZER S10/JIMMY S15 98 (RH front engine compartment)
S10/S15/SONOMA 98 (4.3L)
BRAVADA 98 (4.3L)
ENVOY 98 (RH front engine compartment)
ISUZU HOMBRE 98 (4.3L)
Note: Some 1998 models require checking for build date option ZN4. This part fits models WITHOUT this option. Please verify your specific application.
Frequently Asked Questions
Do I need to do anything after I install it?
Because this PCM comes pre-programmed to your VIN, no dealer flashing is needed. However, you will likely need to perform a simple ‘Security Relearn’ or ‘Crankshaft Variation Relearn’ procedure, which can be done without special tools. Instructions are widely available online for your specific model.
Is this a new part?
No, this is a fully functional, tested computer module sourced from a salvaged vehicle. This allows us to offer a reliable, cost-effective solution compared to a brand new unit from a dealer, which can be prohibitively expensive.
How do I know if my PCM is actually bad?
Common signs include a no-start condition where the engine cranks but won’t fire, multiple unrelated trouble codes, or a specific code like P0601. The best way to be certain is with a proper diagnosis from a qualified mechanic, but the symptoms listed on this page are strong indicators.
What happens if I don’t provide my VIN?
We cannot ship the module until we have your VIN. The programming is essential for the part to function correctly in your vehicle. It ensures compatibility with your engine, transmission, and factory options. Please provide your 17-digit VIN during or after checkout.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls engine performance and transmission shift points. If the module is sending incorrect data, it can cause hard shifts, delayed shifting, or hunting for gears. If the root cause is electronic, this module is the correct fix.