ECM F/A1000, Instruction Manual

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4
Power
The F/A Monitor requires clean DC power of 11V to 28V at 1.4A (steady-state). During
sensor warm-up, the requirement is approximately 5A for a period of up to 1 minute. A good
car or motorcycle 12V battery can meet these specifications. An AC/DC power supply is
available (P/N 1000A-7). The supplied wiring harness must be connected directly to the
power source. Do not modify the wiring harness without first contacting ECM.
Warm-up
After powering-up the F/A Monitor, it will take approximately 30 seconds for the control
module to bring the UEGO sensor to its operating temperature. It is okay to have the engine
running during this period. It fact it is recommended that a cold engine be started for a short
period (i.e. one minute) before the F/A Monitor is powered-up. The reason for this is to
allow any condensed water to be cleared from the exhaust system. Any liquid can thermally
shock the UEGO sensor.
For applications where the sensor is mounted in a tailpipe probe, it is especially important to
make sure that all condensed water is out of the tailpipe before the tailpipe probe is inserted
into the exhaust.
Analog Output
The F/A Monitor has a 0V to 5V linearized output suitable for input into a data acquisition or
engine control system. The analog output is available from the female BNC connector on the
wiring harness. For the F/A1000 only, the shell of the connector is signal ground and it is
electrically connected to the power source ground.
The relationship between the analog output (Vout) and the F/A for gasoline
1
is:
F/A = -0.014 x Vout + 0.125 [Equation 1]
For example, if Vout is 4.0V then the F/A is 0.069.
When the F/A Monitor is first turned on, the output passes through a sequence of three
voltages. Each voltage is held for five seconds. For the F/A1000, these three voltages are
0.0V, 4.02V and 5.0V, and correspond to 0.125, 0.069 and 0.055 F/A respectively. For the
F/A1500, the three voltages are 0.5V, 4.02V and 4.5V, which correspond to 0.118, 0.069, and
0.062 F/A respectively. The purpose of this sequence is to verify correct electrical
connection and signal conversion with the F/A Monitor and the data receiving device.
1
Assumes fuel H:C ratio of 1.85. For other fuels, see “Fuel Type Compensation”.