FAQ's (related to the SS in most cases)

What is a Tune? A tune is reprogramming of your trucks modules (ECM, TCM or both). This requires that you either send your trucks current modules in or buy an extra set to have programmed. The other option is taking your truck to a local tuner and having it done at their facility. A tune can control most aspects of how your truck drives including performance, fuel economy and shifting.

Inside the "tune" the tuner has the ability to do other things including reprogram for electric fans, change speedo settings to compensate for different tires, set (or remove) the speed limiter, etc.

What is a CAI? The Trailblazer SS intake system (the part that connects the throttle body on the intake manifold to the air filter) is called the cold air intake also known as CAI. There are a half dozen vendors that sell a CAI that is supposed to have less restriction and flow better.

Where are the modules and are they easy to change, replace, etc ? They are located under the hood down low between the battery and radiator. Click here for details

Keep in mind that if you install a different ECM module (not the ones that came from factory) you need to do a couple things. First you need to learn the security key (if the modules have been used in another truck) and finally you need to do a crank relearn in most cases.

  • Security key relearn. This is a simple process that involves cycling through a set of ignition on/off settings 3 times. This can take a up to 30 minutes.

    1. First, insert the ignition key and turn the ignition switch to the “On” position (Do not start the engine). Leave the switch on for 10 minutes. The security light may flash or be on steady during this 10 minute period. Make sure the light is no longer on or flashing before proceeding to #2 .
    2. Turn the ignition switch off for 30 seconds.
    3. Turn the ignition switch to the “On” position (as in step #1) for 10 minutes again.
    4. Turn the ignition switch off for another 30 seconds.
    5. Turn the ignition switch to the “On” position for 10 minutes a third time.
    6. Turn the ignition switch off for 30 seconds one final time.
    7. Turn the ignition switch to the “On” position one final time and wait 30 seconds.

  • Crank Relearn. This is something that requires special tools to do and can be done at the dealer or by anyone with the proper tools. This is REQUIRED. It should only take a few minutes and most dealers should not charge much. For those with HPtuners or the DashHawk, you can do it yourself. Follow the instructions included with each device. Some companies like PCM of NC offer DashHawk loaner programs so you can do this procedure yourself.

What is torque management (TM) ? This is something that GM has added to the programming to protect the transmission during shifts. It is the general consensus that GM has added an excessive amount which reduces the performance. Most tuners will remove a certain amount of TM or all at your request. The computer actually detune's the motor at shift points to make this happen.