Restore Peak Performance to Your Allison Transmission
Is your 2001-2005 Silverado or Sierra HD truck experiencing erratic shifting, getting stuck in one gear, or displaying a transmission-related check engine light? These are classic symptoms of a failing Transmission Control Module (TCM). The TCM is the electronic brain of your Allison 1000 5-speed automatic transmission, and when it malfunctions, it can cause a host of frustrating and potentially damaging issues. This replacement TCM, part number 29537441, is the definitive solution to get your powerful truck back to shifting smoothly and reliably.
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra expense out of the repair by pre-programming the module specifically for your truck. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) after your purchase, and our technicians will flash the module with the latest, most stable software updates directly from GM. This ensures perfect communication between the engine, transmission, and other vehicle systems, restoring the precise shift logic your truck had from the factory.
Diagnosing a Faulty 2001-2005 Silverado TCM
A failing TCM can manifest in several ways, often confused with internal transmission problems. Before condemning your transmission, check for these common electronic faults. A faulty module is a frequent point of failure on these otherwise legendary workhorse trucks, often due to its location on the fan shroud where it’s exposed to constant heat and vibration.
From the Diagnostic Bay
We had a 2004 Sierra 2500HD come in on the hook. The owner said it was stuck in ‘limp mode’ (third gear) and he was convinced his Allison transmission was shot. The dash was lit up with warnings. After hooking up our scanner, we saw multiple communication error codes (U-codes) pointing to the TCM. Instead of a multi-thousand dollar transmission job, the fix was this exact part. We programmed the new module to his VIN, installed it in under an hour, cleared the codes, and the truck was shifting perfectly. He was back on the road, relieved it was a simple electronic fix.
Common Symptoms of a Bad TCM:
- ✔ Harsh or delayed shifting
- ✔ Transmission getting stuck in one gear (limp mode)
- ✔ Check Engine Light or Transmission Warning Light illuminated
- ✔ Diagnostic Trouble Codes (DTCs) related to shift solenoids, sensors, or communication errors (e.g., P0700, P0751, P0842)
- ✔ Inaccurate gear display on the instrument cluster
- ✔ Complete loss of gear engagement
- ✔ Poor fuel economy due to incorrect shift points
A True Plug-and-Play Solution
Replacing your 2001-2005 Silverado TCM with this unit eliminates the need for an expensive trip to the dealership for programming. The module arrives at your door ready for installation. Located on the driver’s side of the radiator fan shroud, replacement is straightforward for a DIY mechanic with basic tools. Once installed, the module will immediately recognize your vehicle’s specific configuration, allowing for a seamless repair process.
This module is a direct replacement for a wide range of original equipment service numbers, ensuring broad compatibility. Please verify that one of the following service numbers is printed on your original module:
Compatible Service Numbers (SERV NO): 15768288, 15071240, 15163072, 15163073, 15169833, 15169834, 15169835, 15183963, 15187103, 15187104, 29537441, 09385220, 09387820.
Vehicle Fitment:
- 2001-2005 Chevrolet Silverado 2500/3500 Pickup: with 5-Speed Allison Automatic Transmission (RPO Code M74)
- 2001-2005 GMC Sierra 2500/3500 Pickup: with 5-Speed Allison Automatic Transmission (RPO Code M74)
Frequently Asked Questions
Do I need to program this module?
No. This Transmission Control Module comes fully programmed to your vehicle’s specific VIN. We handle all the programming before it ships, so it’s ready for installation right out of the box.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your 17-digit VIN. We cannot ship your part until we receive this information, as the programming is specific to your truck.
Where is the TCM located on my truck?
On the 2001-2005 Silverado and Sierra HD trucks, the TCM is typically mounted on the driver’s side (LH) of the radiator fan shroud in the engine bay.
Is this a guaranteed fix for my transmission problems?
While this module corrects a very common point of failure, proper vehicle diagnostics are always recommended. If your truck is showing symptoms listed above, and especially if you have communication-related DTCs, a faulty TCM is the most likely cause.
Will this part work for the 6-speed Allison?
No, this module is specifically for the 5-speed Allison 1000 series transmission (option code M74) found in 2001-2005 model year GM HD trucks. It is not compatible with the later 6-speed models.