Page 1 of 1

TRIM Gauge with E-TEC 90

Posted: Sun Jan 07, 2018 10:23 am
by jimh
The Evinrude legacy E-TEC 90-HP (and other three-cylinder in-line) engines do not provide engine trim in their NMEA-2000 data from the EMM. If an individual gauge to display engine trim position is desired, an analogue or conventional gauge must be used. If the wiring harness for the rigging was chosen to be the I-COMMAND WIRING HARNESS, there will be a problem: no wiring is provided for a conventional gauge. This can be overcome by modification to the wiring harness. This article will explain the modification.

The stock Evinrude I-COMMAND WIRING HARNESS looks like this:

Evinrude I-Command Wiring Harness; from the service manual.
ICOMMAND_Harness_Stock.jpg (76 KiB) Viewed 759 times

Note that there is embedded in the harness at some point a 47-Ohm 5-Watt resistor. To modify the harness, the resistor must be located. Typically the resistor can be found by careful visual and tactile examination of the cable. Once the resistor is located, it must be cut out of the circuit. The TRIM SENSOR circuit must be extended with a new conductor and fitted with a ring terminal conductor. The modified cable will look like this:

Modified I-Command Wiring Harness to break out the TRIM SENSOR circuit
ICOMMAND_Harness_Modified_B.jpg (75.89 KiB) Viewed 759 times

Note that you can leave the 47-Ohm resistor connected to the VIOLET (Switched 12-Volt Accy) circuit, but carefully insulate the free end. It will be difficult to get new wire with WHITE-with-TAN-Stripe color insulation; just use wire with WHITE insulation and mark the conductor with some brown tape cut into small stripes near the ring terminal end.

A conventional trim gauge can now be connected to the modified cable. The new conductor you added goes to the S terminal post; the exiting BLACK conductor with ring terminal goes to the G terminal post; the exiting VIOLET conductor with ring terminal goes to the I (ignition key) terminal post.

Please be aware that in the Evinrude gauge series, the ICON Accessory gauge for TRIM cannot be used with this wiring. That gauge contains a stepper motor and is intended only for connection to an ICON Pro RPM gauge. Only a conventional trim gauge can work in this application. Choose the style of the gauge to match other devices on your helm panel.

Re: ICON Pro RPM Gauge for TRIM with E-TEC 90

Posted: Mon Jan 08, 2018 8:16 am
by jimh
If an ICON Pro RPM gauge is used, you can read the engine trim on the LCD display of the ICON RPM gauge by using one of the analogue inputs to the gauge.

There is a breakout of several individual conductors on the ICON Pro RPM gauge wiring harness. Locate the conductor marked P1-7. This input is typically used for the trim sender.

If the engine wiring harness is the MWS instrument wiring harness, then there is no need to modify the harness. The trim sender circuit is already made available on the conductor WHITE with TAN stripes. If you have the the I-Command wiring harness, it must be modified as shown above to isolate the trim sender conductor.

Locate the trim sender conductor from the wiring harness and connect that circuit to the ICON Pro RPM gauge at its P1-7 conductor in the wiring breakout.

UPDATE: When connecting the ICON Pro RPM gauge analogue input to the trim sender, there should be no external voltage applied to the circuit. The ICON Pro RPM gauge will supply its own voltage to the trim sender to read its resistance. It applies about 1.2-Volts to the circuit.

Next, using the ICON Pro RPM gauge user interface and LCD display, change the configuration of the ICON Pro RPM gauge to use the analogue input at P1-7 for trim. This requires two steps:

First, tell the ICON Pro RPM gauge exactly where the trim sender is connected. This is done by setting the P1-7 analogue input to be the TRIM input.

EDIT --> DATA SOURCES --> ANALOGUE -->P1-7 --> (set to) TRIM

Verify that only the P1-7 input is set to TRIM. Unused analog inputs should be set to "N/C" (no connection).

Next, set the gauge to use a trim sender as the input, and select the trim sensor type to be Evinrude. The path to this configuration in the menu should be


Note that the ICON Pro RPM gauge user interface may jump to this setting all by itself, once you have set one of the analogue inputs to be used for trim.

The default setting may have been NMEA2000; that told the gauge to get trim data from the network; by changing the setting to EVINRUDE you have informed the gauge to get trim directly from a trim sender. Setting to EVINRUDE tells the gauge what the range of resistance values will be encountered in the sensor.

The ICON Pro RPM gauge should now be able to show engine trim on the LCD display. You may have to configure the display set up to include engine trim if that data is not already in the rotation of data to be shown on the LCD display.

Re: TRIM Gauge with E-TEC 90

Posted: Tue Jan 09, 2018 1:52 pm
by jimh
I added some additional advice to the post above regarding the wiring of the trim sender to the ICON Pro RPM gauge analogue input.

Re: TRIM Gauge with E-TEC 90

Posted: Fri Jan 12, 2018 8:19 pm
by jimh
A boater has connected the trim sender of his E-TEC 90 to an ICON Pro RPM gauge and configured the RPM gauge to get input for TRIM from an analogue input as described above. The trim data is displayed on the RPM gauge LCD display, as expected, and, quite surprisingly, a dedicated ICON Accessory two-inch gauge for TRIM also shows the engine trim.

Re: ICON Pro RPM Gauge for Trim and NMEA-2000

Posted: Sat Jan 13, 2018 12:41 pm
by jimh
If the ICON Pro RPM gauge is configured to get TRIM position from its analogue input, the concern is then to know if the data developed from that input is going to be sent back onto the NMEA-2000 network as being the engine trim position, so that other NMEA-2000 display devices can then read the trim position and display the data. As best as I can recall, based on advice from informed sources, I do not believe the ICON Pro RPM gauge will do that. I have performed a bench test to assess this problem. The test was as follows:

An ICON Pro RPM gauge had its analogue input at P1-7 (marked "Trim") wired to a variable resistance. The gauge was configured to read the trim data from the P1-7 input, the sender type was set to "EVINRUDE" and the sender calibration procedure was performed. This was done using the ICON Pro RPM gauge user interface and input buttons.

The details of the wiring were:
    --the P1-7 lead via an 82-Ohm resistor was terminated to ground;
    --this resistor was used in the calibration procedure as the "down" trim position (or "0% TRIM");
    --the 82-Ohn resistor was then shunted with a 47-Ohm resistor, creating an 29.8-Ohm resistor;
    --this value was used for the "up" trim position (or "100% TRIM").
It was then possible to create intermediate readings of trim by shunting the 82-Ohm resistor with other values of resistance greater than 47-Ohms, producing intermediate readings of trim between 0 and 100%. For example, shunting with a 100-Ohm resistor created a 45-Ohm resistance, which produced a reading of TRIM = 74%.

ICON Pro RPM gauge LCD display shows trim value.
ICONProRPM_Trim74.jpg (18.76 KiB) Viewed 628 times

(Of course, it would have been simpler to test with an actual trim sender, but I did not have one handy.)

Confident that I had properly set up the ICON Pro RPM gauge to read engine trim data via its analogue input, I then connected the ICON Pro RPM gauge to the bench's NMEA-2000 network. Also on the network was a Lowrance HDS-8 multifunction display.

On the HDS-8 multifunction display, a page was already available to show engine trim data, having been set up to read it from my E-TEC engine. As expected, the trim data from the ICON Pro RPM gauge did not appear. This was expected, for two reasons:
    --the HDS was set up to get its engine data from the E-TEC engine on my boat, and that engine was not on the network;
    --the HDS did find the ICON Pro RPM gauge on the network, but it saw NO DATA coming from the gauge.

The HDS multi-function display showing no trim data on the engine data page.
HDS_DisplayNoTrim.jpg (19.29 KiB) Viewed 636 times

The HDS multi-function display sees the device called ICON Pro RPM gauge on the network.
HDS_DeviceList_ICON_ProRPM.jpg (11.57 KiB) Viewed 636 times

The HDS multi-function display showing no data coming from the ICON Pro device in the network diagnostic screen.
HDS_NetworkDiagnosticNoData.jpg (6.17 KiB) Viewed 636 times

In order for the trim data from the ICON Pro RPM gauge to be available to other devices on the NMEA-2000 network, the ICON Pro RPM gauge would have to send a PGN to the network normally sent by an engine, then include the trim data in that PGN. But the ICON Pro RPM gauge does not send any data at all to the network, or at least no data that the Lowrance MFD diagnostic utility can recognize.

On this basis, I conclude that when the ICON Pro RPM gauge analogue input is used to create engine trim position data, that data is only available on the ICON Pro RPM gauge itself, or on other downstream gauges.

To test if the trim data was available on other downstream gauges in the ICON Pro Series, I tried to configure the ICON Pro SPEEDOMETER gauge to shown the trim data. Unfortunately, the ICON Pro SPEEDOMETER gauge cannot display engine trim, no matter where the data comes from; it just does not have a setting for engine trim among its options for data to display.

The ICON Pro SPEEDOMETER gauge does have a setting for FUEL TANK 1 LEVEL. As it happens, I had already configured the ICON Pro RPM gauge to measure fuel tank level via one of its analogue inputs (P1-6). It was then possible to test if the ICON Pro RPM gauge makes this data available to the ICON Pro SPEEDOMETER. The ICON Pro SPEEDOMETER was configured for one of its display pages to show FUEL TANK 1 LEVEL. And, indeed, the ICON Pro SPEEDOMETER was able to show the fuel tank level data, which was actually coming from the analogue input to the ICON Pro RPM gauge.

While this does not prove that in a similar manner the trim data will be available, it does suggest that. And, indeed, the report (above) of success in seeing the trim data on a dedicated ICON Accessory TRIM gauge confirms that outcome.

Power for E-TEC EMM to Sense Trim Sender

There is a further consideration about using the ICON Pro RPM gauge analogue input to read trim sender resistance: assuming this configuration is used in an E-TEC engine with an EMM that supports reading the trim position from the sender, will the relatively low voltage (about 1.5-Volts) supplied by the ICON Pro RPM gauge analogue connection give enough electrical power to the circuit to permit the E-TEC EMM to also sense the voltage. This was tested on the bench as follows:

The voltage supplied to the trim sender from the ICON Pro RPM gauge was monitored using an accurate DVM, and the resistance of the trim sender was varied. The voltage at the trim sender--the portion of the circuit connected to the E-TEC EMM--was monitored to see if any change occurred. The results were as follows:

TRIM   Vdc at EMM-circuit
1% = 1.253
56% = 0.904
60% = 0.881
74% = 0.782
100% = 0.521

This suggests that a voltage variation of about 0.73-Volts is enough for the ICON Pro RPM gauge to sense the position. With the E-TEC EMM in normal trim sender electrical configuration, the voltage supplied would tend to be much higher. The source of voltage is the battery, or 12-Volts. The series resistance is nominally 47-Ohm. The sender resistance varies from about 10-Ohms to 88-Ohms. That suggests that the normal input voltage for the EMM trim circuit would vary between 2.1 to 7.8-Volts, a much wider range.

Since no E-TEC engine was available on the bench, this configuration could not be tested.