NAG1 tranmission reset & learning

This article is based on NAG1 installation manual. You can download the original and keep it for reference.

TCM ADAPTATION for NAG1 transmission

This procedure allows the electronic transmission system to re-calibrate itself. This will provide the proper baseline transmission operation. The adaptation procedure should be performed if any of the following procedures are performed:

  1. Transmission Assembly Replacement

  2. Transmission Control Module Replacement

  3. Clutch Plate and/or Seal Replacement

  4. Electro-hydraulic Unit Replacement or Recondition

We also recommend it if shifting feels off after:

  1. Changing gears in axles (axle ratio)

  2. Changing significantly the tire size

The procedure

  1. Connect with JScan to your vehicle

  2. Open Adaptations and naviate to the Tire & Axle or Vehicle Maintenance section, or use search to locate “Reset Learned Adaptives (NAG1)” or similarly named adaptation and run it.

  3. Start your vehicle and go for a ride (you will need a highway or a similar road, where you can reach higher speeds)

  4. Drive the vehicle until the transmission temperature is:

    • greater than 60°C (140°F)

    • and less than 100°C (212°F)

    • Failure to stay within these temperature ranges will void this procedure.

  5. Drive until you get the 5th gear, and perform a coast-down (release the gas pedal and let the engine downshift) from 5th to 4th and then from 4th to 3rd gear. Repeat 4 to 5 times.

  6. Stop the vehicle, then moderately accelerate the vehicle and obtain all forward gear ranges while keeping the Engine RPM below 1800 RPM. Repeat this procedure 4 to 5 times.

  7. Obtaining 5th gear may be difficult at 1800 RPM. Allow transmission to shift into 5th gear at a higher RPM then lower the RPM to 1800 and perform manual shifts between 4th and 5th gears using the shift lever.

Warning

The TCM stores adaptives every 10 minutes, so once you complete the process above, make sure that the vehicle stays running for at least 10 minutes OR use “Store learned adaptives” procedure in JScan.