This guide is provided for informational purposes only.  Use this guide to help troubleshoot issues where the ECU is not powering on.  This guide is for ECU's that are compatible with the KTuner In-ECU system. only.

Specifically, use this for the following ECU's/vehicles:

• 2005-2006 RSX (base and Type-S)
• 2003-2005 Accord (4 cylinder only)
• 2006-2007 Accord (4 cylinder only)
• 2004-2006 Acura TSX
• 2003-2006 Element

These ECU's all share the same wiring layout as far as grounds and power, therefore, these can all be verified in the same manner.

Grounds:

Unplug all connectors/plugs from the ECU, and check the following with key OFF:

Pins A4, A5, A8, and A9 should all have continuity to ground.  All of these pins connect to the engine harness ground near the fuel injectors.

Power:

With all connectors/plugs still disconnected from the ECU, turn ignition to 'ON' position and check the following:

Pin E9 should have +12v (battery power)

Switched ECU Power:

With key OFF, plug all ECU plugs/connectors back into the ECU.  Check the following by back-probing the connectors.  Back-probing is done by using the fine tip probes from your multimeter - insert the probe into the back side (wire-side) of the plugs:

Turn ignition ON. ECU pin E7 should have continuity to ground. Pins A2 and A3 should have +12v power.

Pin E7 ground output is the ECU's output signal to the #1 main relay to turn on the relay.

Pins A2 and A3 are the +12v power input to the ECU from the #1 relay.

 

These are all the required power and ground checks that affect the ECU powering on properly.