LS1TECH - Camaro and Firebird Forum Discussion

Camaro and Firebird: How to Reset the ECU

Learn how to reset the ECU to clear the codes your vehicle may have stored.

By Piyush Kayastha - February 26, 2016

This article applies to the Camaro and Trans Am Firebird (1993-2002).

Part of normal vehicle maintenance involves servicing the part and sometimes replacing it. That is mainly the mechanical side of things. On the electrical side of the equation, there are a series of bulbs, fuses, circuits, wires and the all important - ECU; this is the short name for the vehicle "Engine Control Unit." It is responsible for sending signals and responses to different components in the vehicle. That means everything from interior lighting, to how much fuel an injector sprays into each chamber, to how hot the coolant has gotten. Often, when the vehicle finds a problem with some component or another, it will "store" a code. When this occurs, the instrument cluster in most vehicles will illuminate a CEL, MIL, or SES light. The code(s) stored can be read by an automotive diagnostic scanner to determine the problem(s). Most automotive shops will service the issue and once fully repaired, they can usually "clear" the codes using the same diagnostic scanners or by performing a reset of the battery and/or ECU. Sometimes there are issues only resolvable by "reflashing" or resetting the ECU. Many people believe simply pulling the negative cable on the battery is suffice to reset the vehicle's ECU. Read on to learn more about how to properly reset the ECU on your Camaro, Firebird or Trans Am.

Camaro and Firebird How to Reset ECU

Materials Needed

  • Flat head screwdriver
  • Fuse puller
  • Test probe

Step 1 – Turn key to ON position

This step is to have the ECU actively read that the necessary fuses are being reset.

  • Insert key into ignition.
  • Crank key to the ON position, but do not start the car.
turning key to on position
Figure 1. Turn the key to the ON position.

Pro Tip

If your car has a push button start, you would press the button once to illuminate the instrument cluster and not press the brake pedal to crank the motor.

Step 2 – Remove PCM BATT and IGN fuses

To reset the battery and ECU in sync, the fuses need to be removed in order.

  • Open the hood.
  • Locate the fuse box and open the cover.
  • Locate both the PCM BATT and PCM IGN fuses.
  • Use the fuse puller to remove PCM BATT fuse.
  • Use the fuse puller to remove the PCM IGN fuse.
  • Wait ten minutes.
  • Replace fuses in reverse order (PCM iGN fuse first).
  • fuse cover
    Figure 2. Fuse locations on the inner box cover.
  • fuses
    Figure 3. Remove the fuses with a fuse puller tool.

Pro Tip

You will need to reset your clock and/or compass after this procedure is done. During that time, you can also check to see if they are blown.

Step 3 – Determine if codes are cleared

Now that you have reset the ECU, it's time to determine if the codes are reset.

  • Drive the car for a short while.
  • If SES light does not reappear, the codes have been successfully cleared.
  • If SES light does reappear, consider replacing the fuses.
fuses
Figure 4. If problems persist, switch out the offending fuses.

Pro Tip

You can also use a test probe to test fuses to confirm they are blown.

Featured Video: How to Test Fuses

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