Restore Peak Performance to Your GMC Safari
Is your 1998 or 1999 GMC Safari giving you headaches? If you’re dealing with frustrating issues like stalling at stoplights, erratic shifting, a persistent Check Engine Light, or a no-start condition that leaves you stranded, the root cause is often a failing Powertrain Control Module (PCM). As the central computer of your van, the PCM controls everything from fuel mixture and ignition timing to transmission shift points. When it falters, the vehicle’s reliability plummets.
This isn’t just another part. This is a dependable, fully programmed solution. We take the guesswork and high dealership costs out of the equation. By providing your vehicle’s VIN at checkout, you receive a PCM that is flashed with the latest GM software updates specific to your Safari. This ensures it communicates perfectly with your engine, transmission, and all related sensors right out of the box. Getting your trusted workhorse back on the road has never been more straightforward.
A Technician’s Notebook: The Phantom Problem
I remember a 1999 Safari that came into my bay with a complaint of intermittent stalling and a hard 1-2 shift. The owner had already replaced the fuel pump and a handful of sensors with no luck. The scan tool showed a few communication codes but nothing consistent. After checking the wiring harnesses for the third time, I focused on the PCM. On these vans, heat cycles and vibrations eventually cause microscopic cracks in the PCM’s circuit board. We swapped in a VIN-programmed module, and it was like a different vehicle. All the phantom issues disappeared. It’s a classic case where chasing symptoms is a waste of time and money; the solution is to address the vehicle’s brain.
Is Your Safari Showing These Signs of a Failing PCM?
- ✔ Unexplained Check Engine Light, often with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Harsh, erratic, or delayed automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Intermittent stalling, especially when coming to a stop or at idle.
- ✔ The engine runs rough, misfires, or hesitates during acceleration.
- ✔ Communication errors with your scan tool.
Your Straightforward Installation Guide
Replacing the PCM on your GMC Safari is a job most DIYers can handle in their own driveway. On these models, the PCM is typically located in the engine compartment on the driver’s side, near the battery.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
- Locate the PCM: Find the module near the battery. It will have several large multi-pin electrical connectors attached.
- Disconnect Connectors: Carefully unlatch and remove all electrical connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few bolts or nuts.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it.
- Reconnect Everything: Firmly plug all the electrical connectors back into the new module until they click into place. Reconnect the negative battery terminal.
- Final Step: Start the vehicle. It may take a moment to idle smoothly as it completes its initial learning cycle. Your Safari is ready to drive!
Verified Fitment For Your Vehicle
This Powertrain Control Module is a direct-fit replacement for several GM vehicles. Please verify your original part number matches one of the compatible numbers below. This module is guaranteed to fit your 1998-1999 GMC Safari and is also compatible with the following models:
- Part Numbers: 09355699, 16250279, 09366810
- GMC Safari: 1998-1999
- Chevrolet Astro: 1998-1999
- Cadillac Escalade: 1999
- Chevrolet & GMC Pickups (1500/2500/3500): 1998-1999 (Gasoline engines)
- Chevrolet & GMC Suburban/Tahoe/Yukon: 1998-1999 (Gasoline engines)
- Chevrolet Express & GMC Savana Vans (1500/2500/3500): 1998 (Gasoline engines)
- Chevrolet S10 / GMC Sonoma / Isuzu Hombre: 1998 (4.3L V6)
- Oldsmobile Bravada / GMC Envoy / Chevrolet Blazer / GMC Jimmy: 1998 (4.3L V6)
Note: Always match your service ID number (e.g., 16250279) on your original module to ensure perfect compatibility.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to flash the PCM with the exact software and calibrations your 1998-1999 GMC Safari PCM requires. This includes specifications for the engine, transmission, and any factory options, ensuring a true plug-and-play installation without needing a trip to the dealer.
Is this part difficult to install?
Not at all. For most DIY mechanics with basic hand tools, this is a one-hour job. The PCM is easily accessible in the engine bay. Just disconnect the battery, swap the modules, reconnect, and you’re done.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the transmission’s electronic solenoids and determines shift points. If your hard or erratic shifting is caused by a faulty computer, this replacement module will resolve the issue.
Do I need to perform a security relearn procedure?
For most GM vehicles of this era, a security relearn (often called a Passlock relearn) may be necessary. It’s a simple procedure that takes about 30 minutes and involves cycling the ignition key. We include instructions to guide you through it.
What if my original part number is 16250279?
This module, part number 09355699, is a fully compatible and interchangeable replacement for service number 16250279. It will function identically once programmed to your VIN.