New for 2018!   ETC Tester  - Electronic Throttle Control Tester


· ETC Electronic Throttle Control test system for testing all drive-by-wire Harley Davidson® twist grip sensors and throttle body actuators.

· Uses any PC for display. Includes software for Windows XP/Vista/7/8/10




**ETC Tester includes electrical harness, power supply and software.
The twist grip assembly, throttle body and TCFI6 ECU sold separately.



ETC Test Software main display:






Order online using Paypal or call us at 386-322-7390  (Monday-Friday 9 AM to 5 PM Eastern time) for credit card and COD orders. For online orders, please email any special instructions to 


All products covered by our 1 year limited warranty.


Part Number Description Suggested Retail
Electronic Throttle Control Harness for TCFI Gen 6 (requires customer supplied TCFI Gen 6 ECU, usb interface, twist grip and throttle body assembly). $TBA.00

18018 Electronic Throttle Control Test System includes TCFI 6 ECU and USB interface (requires customer supplied twist grip and throttle body assembly). $TBA.00






The ETC Test has two main options that allow you to test the electronic throttle control system without the engine running:

1) Manual test. Throttle control actuator (TCA) throttle position follows twist grip sensor (TGS) command. This option is useful for a quick check of TCA operation. Click 'Manual Test' to enable ETC manual test mode. The program will then display real time of the TGS and TPS data.


2) Characteristic curve. The system plots out the characteristic curve of TCA throttle position versus TCA motor pulse-width modulated (PWM) drive. This option allows detection of defects such as excessive friction, incorrect or noisy TPS signals, and broken gear teeth. Click on the Start Characteristic Test button to begin the test process that will require approximately 1 minute to complete. A typical characteristic curve for a properly functioning throttle body is shown below. The red trace shows the primary rising sensor (TPS1) voltage level versus TCA motor PWM drive. The green trace shows the sum of the rising and falling sensors (TPS1 and TPS2) versus TCA motor PWM drive. Test parameters including TPS1 levels corresponding to zero, limp back and wide open position are also reported. Refer to the ETC Tester instructions for more details.

Interpreting Characteristic Curve Data:
The red trace shows the hysteresis loops caused by friction and spring tension in two regions, above and below limp back position (refer to the figure below). Each test cycle starts at zero PWM with the TCA at limp back position (approximately 0.75V). TCA PWM is stepped to 40%. At approximately 15% PWM, motor torque is sufficient to overcome spring tension and friction and the throttle starts to open. TPS1 rises to approximately 4.75V (wide open throttle) at approximately 30% PWM. Next, PWM is stepped back down to zero. As PWM drops down below approximately 12%, friction effects are overcome and spring tension closes the throttle back to limp back position. TCA PWM is then stepped in the negative direction to -40%. At approximately -20% PWM, motor torque is sufficient to overcome spring tension and friction and the throttle starts to close. TPS1 falls to approximately 0.5V (closed throttle) at approximately -23% PWM. At the end of each test cycle, TCA PWM is stepped back to zero and the throttle returns to limp back position. The traces for multiple test cycles should overlap closely.

The green trace showing the sum of TPS1 and TPS2 should always be very close to 5.0V. The resistive TPS elements can wear out and become noisy, like a scratchy volume control on an old radio. This noise will appear as wiggles or jumps in the green trace.

A broken gear tooth near limp back position is a common failure mode. The figure below shows the effect.



Download ETC Test Instructions

Download ETC Test Software 


The ETC Test software runs under Microsoft Windows XP/Vista/Win7/Win8/Win10. We no longer support older Windows versions. Minimum PC requirement is a 300 MHz Pentium with super VGA display (SVGA with 1024 x 768 pixel resolution). The ETC Tester connects to the PC by means of a USB interface. A USB cable is supplied with the unit. The PC must have a free USB port. If you have an older PC without USB capability, you cannot use the ETC Tester. For more detailed product information, we suggest that you download the ETC Test software and instructions.








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Rev ETC_Tester_web 1.0.2  3/22/2018