If your late-90s GM truck or van is suddenly running rough, stalling, or refusing to start, the problem often points to the heart of its electronic system: the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen countless vehicles sidelined by a failing PCM. This isn’t just an inconvenience; it affects everything from fuel economy to transmission shifting. This listing offers a reliable and straightforward solution: a tested, used OEM PCM with service number 09355699, fully programmed to your vehicle’s specific VIN.
Forget the expensive trip to the dealership and the hassle of coordinating programming. We handle the critical software flashing for you before it ships. By providing us with your Vehicle Identification Number (VIN) after purchase, we ensure this module arrives loaded with the latest GM software updates for your exact vehicle. This makes the replacement process as close to plug-and-play as possible, getting your trusted truck or van back to peak operational condition.
Case Study: A Tricky Diagnosis
I remember a 1999 GMC Yukon that came into my bay with a classic intermittent no-start condition. The owner had already replaced the battery, alternator, and starter. The scan tool showed a P0601 (Internal Control Module Memory Check Sum Error), but only sporadically. After verifying all power and ground circuits to the PCM were solid—a crucial first step—we swapped in a known-good, programmed module like this one. The problem vanished instantly. The original PCM’s internal processor was failing under certain temperature conditions, a common issue in these older units. This part was the direct, effective fix.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, a faulty module could be the culprit. Look out for these common symptoms and diagnostic trouble codes (DTCs):
- ✔ Check Engine Light is illuminated with codes like P0601, P0605, or P0606.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling.
- ✔ A noticeable decrease in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with your scan tool.
- ✔ The anti-theft or security light stays on, preventing startup.
A Straightforward Guide to Your PCM Swap
Replacing the PCM on these GM vehicles is a manageable job for a confident DIYer. While this 1999 Escalade PCM is programmed for your vehicle, a security relearn procedure is typically required after installation. Always consult a service manual for your specific model, but here are the general steps:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, often on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unclip and remove the electrical connectors from the old PCM. Inspect the pins 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 new, pre-programmed PCM into the bracket and securely reconnect the electrical harnesses.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Security Relearn: This is a critical step. The common procedure involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. This allows the new PCM to sync with your vehicle’s anti-theft system.
Verified Vehicle Compatibility List
This module is a direct replacement for service number 09355699 and is compatible with other part numbers such as 16266645, 16250279, 16258815, and 9366810. It fits a wide range of 1998 and 1999 GM vehicles. Please verify your original part number and check the list below to ensure proper fitment.
Chevrolet Trucks: C/K 1500, 2500, 3500 (1998-1999), S10 (1998), Blazer (1998), Suburban 1500/2500 (1998-1999), Tahoe (1998-1999)
GMC Trucks: C/K 1500, 2500, 3500 (1998-1999), Sonoma (1998), Jimmy (1998), Yukon (1998-1999), Envoy (1998)
Chevrolet Vans: Express 1500, 2500, 3500 (1998-1999), Astro (1998)
GMC Vans: Savana 1500, 2500, 3500 (1998-1999), Safari (1998)
Oldsmobile: Bravada (1998)
Isuzu: Hombre (1998)
Note: Specific engine and option codes apply. This part fits models with ID 9355699.