89195213S Mercury ECM, Engine Control Module

Illustration 1 g01306182The calibration procedure adjusts both of the potentiometers on the converter. The procedure also secures the offset potentiometer in place once the adjustments have been made. The procedure ensures that the converter is properly calibrated.A functional test that verifies the zero, the middle point, and the maximum of the performance curve is performed at the factory. The functional test checks the operation of the converter.
Table 1
Required Tools Qty
146-4080 Digital Multimeter Gp 1
9S-3263 Thread Lock Compound 50 mL (1.70 oz)
N/A Loctite Threadlocker 290
N/A 0 – 200 mA Current source
Do not exceed 230 mA of current into the converter input. Electrical damage to the module will occur.
Remove electrical power from the Electronic Instrument Panel (EIP).
Illustration 2 g01304591
Typical example
(1) "OFFSET" potentiometer
(2) "SPAN" potentiometer
Remove the input wire for the system and any input signal that is connected to terminal 1 of the converter.Note: Do not remove the wires from terminal 10 or from terminal 12. Terminal 10 and terminal 12 are the outputs for the converter. For proper operation of the converter, terminal 10 and terminal 12 must remain connected to the ECM. The converter will not function without completing the above circuit.
Restore power to the EIP.
Use the 146-4080 Digital Multimeter Gp to measure the duty cycle of the converter output. The duty cycle of the converter output is measured across terminal 10 and terminal 12.
Verify that the input wire is disconnected from terminal 1. Adjust "OFFSET" potentiometer (1) to provide a 5 percent duty cycle. Once the potentiometer is set for an output of 5 percent duty cycle, apply Loctite Threadlocker 290 to secure the potentiometer in place. Securing the potentiometer at 5 percent will ensure that the offset is calibrated correctly.Note: When an external current source is used for testing, disconnect the signal lines from the Silicon Controlled Rectifier (SCR). Also, do not operate the engine when you are using the external current source. Accidental high current surges may produce an engine overspeed.
Use a 0 – 200 mA current source. Apply a full 200 mA signal to terminal 1 and to terminal 3 of the converter. Adjust "SPAN" potentiometer (2) to achieve a reading of 85 percent 2 percent duty cycle.
Table 2
Correlation of Input to Input
Input (Milliampere) Output (percent duty cycle)
0 5 2 %
20 13 2 %
60 29 2 %
100 45 2 %
160 69 2 %
200 85 2 %
Table 3
Specifications
Input signal range 0-200 mA Direct Current (DC).
Output signal range PWM 5-90%
Max input current 225 mA
Supply voltage 15-45 VDC
Temperature range −40 °C (−40 °F) to 85 °C (185 °F)
PWM frequency 485 Hz
PWM active state Active high (external pull up to positive DC voltage
Adjustments Span and offset
Repeat Step 3 through Step 6 until the duty cycle is adjusted to the values in Table 2.
Remove electrical power from the EIP.
Reconnect the signal wire or wires to terminal 1 of the converter.
Illustration 3 g01306214
(3) 7S-1198 Screws
Apply a small amount of 9S-3263 Thread Lock Compound to screws (3).Torque for the screws (3)Torque ... 1.7 0.25 N m (15 2 lb in)
Restore power to the EIP.
Start the engine and operate the engine.Note: The engine speed is now controlled by the 0-200 mA signal.