AEM 30-6821 Series 2 Plug & Play EMS - Manual (Page 9)

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EMS Idle Control Calibration
The ETC idle control can be configured and calibrated via the AEMTuner software similarly to more traditional
systems that use an idle air bypass valve. There are a few calibration options that are set specifically to allow
proper ETC idle control and must not be changed from the values set forth in the 30-1820 startup calibration.
The options listed below must remain set as depicted for predictable ETC idle control. The other options that
are not highlighted have been set up for stable idle control in the 30-6820 startup calibration but are, however,
available for adjustment as the calibrator sees fit.
Idle On if TP Less = 13%
Idle Off if TP Over = 13%
Idle Invert = ON
Idle FB Dir Invert = ON
Idle PW Frequency = 10000.0 uS
ETC Fault Management
The ETC system continuously monitors itself for proper operation. If a fault is detected then the system will be
placed in a failsafe mode and power to the electronic throttle body will be turned off. This will allow the engine
to start and idle at approximately 1500-
2000 rpm as a “limp-home” mode but the throttle body will not respond
to accelerator pedal inputs.
The system will continue to monitor itself and assume that the throttle blade will be in its rest position while in
this un-powered failsafe mode. If it is detected that this is not the case then the system will enter a second
failsafe stage whereby the crank signal to the EMS is interrupted. The tachometer will drop to zero and the
EMS will not fire fuel injectors or ignition coils. If the engine is running, it will coast to a stop. If the engine is not
running, it will not start.
ETC Diagnostics
The AEM EMS ETC system uses the CRUISE and SET indicator lights on the dashboard to display diagnostic
information to the user. The indicator lights flash in different ways for different purposes as described in the
following sections.
Figure 9 - CRUISE and SET Indicator Lights as diagnostic outputs
Boot-Up
When the ignition key is turned on and the EMS is powered up, both of the CRUISE and SET indicator
lights will flash briefly to signify the ETC system has booted up and that the indicator lights are
functioning properly.
Fault Detected
When the ETC system detects a fault, the CRUISE and SET indicator lights will flash in an alternating
fashion to alert the user a fault has been detected. This will happen in one of two situations:
1. Calibration Fault – A failed calibration will be detected if one of the sensors is found to be out of
the expected range during the calibration procedure. The indicator lights will flash in an
alternating pattern to alert the user of this fault for a period of approximately twenty (20)
seconds. After this time period, the CRUISE light will remain off and the SET indicator light will
flash a fault code. Please reference Table 1 for a description of the fault codes. The system
will flash the code repeatedly until the ignition is turned off.