Restore Your Truck’s Shifting Performance and Reliability
If you’re dealing with the frustration of a GM HD truck that slams into gear, hesitates, or is stuck in limp mode, you know how disruptive it can be. As a technician with over two decades of experience, I’ve seen countless 2001-2005 Silverado and Sierra trucks sidelined by a faulty Transmission Control Module (TCM). The Allison transmission is a legendary workhorse, but its brain—the TCM—can fail, leading to erratic behavior that makes your powerful truck feel unreliable. This isn’t just an annoyance; it’s a critical failure that impacts your ability to tow, haul, and depend on your vehicle.
This is your direct-fit, hassle-free solution. We are offering a genuine replacement Transmission Control Module, part number 15169835, that arrives at your door fully programmed to your truck’s specific VIN. Forget about expensive tow bills to the dealership or paying exorbitant fees for programming. Simply provide us with your VIN at checkout, and we’ll flash the module with the latest, most stable GM factory software. This ensures perfect communication between your engine and transmission, restoring the crisp, predictable shifting you expect from your Allison transmission.
A Technician’s Notebook: The Misleading U-Code
I once had a 2004 Sierra 2500HD in the bay with a classic ‘no communication with TCM’ code (U0101). The owner had already replaced the ignition switch and checked all the main power and ground wires, convinced it was a wiring issue. After confirming the TCM had power and ground, we found the module itself was internally shorted. It was pulling down the entire communication network, causing other random warning lights. Replacing the TCM with a pre-programmed unit like this one not only fixed the transmission issue but also cleared up two other seemingly unrelated codes. It’s a great reminder that the TCM is the central hub for your truck’s powertrain communication.
Is Your Allison Transmission Showing These Symptoms?
- ✔ Harsh or delayed shifting between gears.
- ✔ The truck feels stuck in one gear (often called ‘limp mode’).
- ✔ A lit Check Engine Light or Transmission warning light on your dash.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0700 (Transmission Control System Malfunction), P0751, P0756, or communication codes like U0101.
- ✔ Inaccurate or erratic speedometer readings.
- ✔ A feeling of lost power or poor fuel economy directly related to shifting problems.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the TCM: On these GM HD trucks, the TCM is typically mounted on the driver’s side of the fan shroud in the engine bay. It’s a silver box with large electrical connectors.
- ✔ Disconnect Connectors: Carefully unclip and remove the large electrical harness connectors from the old TCM. Inspect them for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old TCM from its mounting bracket on the fan shroud. It’s usually held in place by a few small bolts.
- ✔ Install the New Module: Mount your new, pre-programmed TCM onto the bracket and securely fasten the bolts.
- ✔ Reconnect and Secure: Plug the electrical connectors firmly into the new module until they click into place. Reconnect your battery’s negative terminal.
- ✔ Final Check: Start the vehicle and allow it to idle for a moment. The new module will sync with your truck. Take it for a test drive to confirm that shifting has returned to normal. No further programming is required.
Guaranteed Fitment for Your GM HD Truck
This module is a direct replacement for service numbers 15768288, 15071240, 15163072, and others listed below. It is specifically designed for the following vehicles equipped with the 5-speed Allison automatic transmission (RPO code M74):
- 2001-2005 Chevrolet Silverado 2500 HD & 3500
- 2001-2005 GMC Sierra 2500 HD & 3500
This part is a direct replacement for the following service numbers: 15768288, 15071240, 15163072, 15163073, 15169833, 15169834, 15169835, 15183963, 15187103, 15187104, 29537441, 09385220, 09387820.
Frequently Asked Questions
Do I need to do any programming after I install this?
No. This is the biggest benefit of our service. We program the module to your vehicle’s VIN before we ship it. It arrives ready for installation with no extra steps needed.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.
Is this a reliable fix for limp mode?
Yes, a failing TCM is one of the most common causes of a transmission going into ‘limp mode’ on these trucks. Replacing it with a properly functioning, programmed module is the correct repair for this specific failure.
How do I provide my VIN to you?
After you complete your purchase, you will receive instructions on how to send us your VIN. We cannot ship the part until we receive and program it with your information.
What if my part number isn’t 15169835 but is on the compatible list?
That’s perfectly fine. Manufacturers often update part numbers. As long as your existing module’s service number is on our compatibility list, this module is the correct, updated replacement for your truck.