Restore Your Vehicle’s Brain and Get Back on the Road
If your GMC Safari, Chevy Express, or other compatible GM truck is suffering from frustrating issues like stalling, erratic idling, a persistent Check Engine Light, or a complete no-start condition, the problem often lies with a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty PCM can cripple an otherwise solid vehicle. This isn’t just an inconvenience; it affects fuel economy, emissions, and overall drivability. This module, part number 9355699, is the central computer for your engine, and when it fails, nothing works right.
We offer a straightforward, reliable solution. This is a thoroughly tested, used OEM Powertrain Control Module that we program specifically to your vehicle’s Vehicle Identification Number (VIN). By providing your VIN at checkout, you receive a module with the latest GM factory software updates already loaded. This eliminates the need for expensive dealership programming or specialized tools, making it a direct-fit replacement that gets your vehicle running smoothly again. This is the most efficient way to solve complex electronic issues and restore the performance you depend on.
Is Your GM Truck or Van Showing These Symptoms?
- ✔ Unexplained Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module Read Only Memory (ROM) Error).
- ✔ The engine cranks but refuses to start.
- ✔ Rough or unpredictable idling and stalling.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Harsh or incorrect shifting from the automatic transmission.
- ✔ No communication with your OBD-II scan tool.
- ✔ Intermittent issues that seem to have no other cause.
A Technician’s Notebook: The Intermittent No-Start Mystery
A 1999 Chevy C1500 with a 5.7L V8 came into my bay with a classic head-scratcher: it would start perfectly for a week, then refuse to start for a day. The owner had already replaced the battery, starter, and fuel pump. When I connected my scan tool, I had no communication with the PCM. This is a huge red flag. After checking the power and ground circuits to the module, which were solid, I knew the PCM itself was the culprit. Heat soak and aging internal solder joints on these older modules often cause intermittent connection failures. We installed a VIN-programmed PCM like this one, and the truck fired up on the first try and never had the issue again. It saved the customer from chasing phantom problems and got his work truck back in service fast.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the PCM: On most of these vehicles (like the GMC Safari or Astro), the PCM is located in the engine compartment on the driver’s side, often near the battery or firewall. In vans like the Express/Savana, it may be in the LH rear engine compartment.
- ✔ Disconnect the Harnesses: Carefully unclip and remove the electrical wiring harnesses connected to the old module. These connectors have locking tabs that need to be released gently.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new unit.
- ✔ Install the New Module: Mount your new, pre-programmed PCM using the original hardware. Ensure it is secure.
- ✔ Reconnect Everything: Plug the wiring harnesses firmly into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Steps: Your vehicle may need to complete a security relearn procedure, which is typically straightforward. In most cases, you can simply turn the key to the ‘ON’ position for 10-15 minutes before starting. Your vehicle is now ready to drive.
Verified Vehicle Compatibility for Part 9355699
This module is a direct replacement for service number 9355699 and is interchangeable with part numbers 16266645, 16250279, 16258815, and 09366810. It is guaranteed to fit a wide range of 1998-1999 General Motors trucks, vans, and SUVs. Please match your original part number or verify fitment with your vehicle’s specific model and engine below. This is a partial list of compatible vehicles:
- ✔ 1998-1999 Chevrolet & GMC C/K 1500, 2500, 3500 Pickups (Gasoline)
- ✔ 1998-1999 Chevrolet Suburban & Tahoe (Gasoline)
- ✔ 1998-1999 GMC Yukon & Yukon XL (Gasoline)
- ✔ 1998-1999 Chevrolet Express & GMC Savana 1500, 2500, 3500 Vans (Gasoline)
- ✔ 1998 Chevrolet Astro & 1998 GMC Safari PCM
- ✔ 1999 Cadillac Escalade
- ✔ 1998 Oldsmobile Bravada, Chevrolet S10 Blazer, GMC S15 Jimmy/Envoy, Isuzu Hombre (4.3L V6)
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming before shipping. We will flash the module with the latest GM software updates using the VIN you provide, so it arrives ready for installation.
Why do you need my VIN?
The VIN (Vehicle Identification Number) allows us to load the exact software calibration for your vehicle’s specific engine, transmission, and options. This ensures perfect compatibility and performance.
Is this a new part?
No, this is a high-quality, tested used OEM (Original Equipment Manufacturer) part sourced from a salvaged vehicle. This provides OEM reliability at a fraction of the cost of a new unit.
Will this fix my vehicle’s specific problem?
This PCM will resolve issues directly caused by a faulty module. While the symptoms listed are common indicators, we always recommend a proper diagnosis by a qualified mechanic to confirm the PCM is the point of failure before ordering.
What is the security relearn procedure?
For most of these GM vehicles, it involves turning the ignition key to the ‘ON’ position (without starting the engine) for about 10-15 minutes. This allows the new PCM to synchronize with your vehicle’s anti-theft system. The security light on the dash should turn off when complete.