Mercury V6 175 Diagnostic Manual page 158

Sensors
NOTE: During normal operation, exhaust gas temperature should be less than 300 °C (572 °F).
CDS G3 Interface Kit
If there is not an obvious change in exhaust gas temperature sensor values, shake or move the sensor harness and connector.
If the temperature begins to change, look for a broken, loose, or corroded wire.
Continue testing with the engine OFF:
1. Disconnect the engine harness from the sensor harness.
2. Perform a visual inspection of the sensor pins and the wires coming from the connector. Look for broken, bent, or corroded
pins at the sensor and loose, broken, or corroded wires at the connector.
3. Test the sensor with an ohmmeter.
a. Remove the sensor from the exhaust manifold.
b. Immerse the tip of the sensor in a controlled temperature medium. If the readings do not match those in the table,
replace the sensor and retest.
b
a
DMT 2004 Digital Multimeter
4. Perform a continuity check of the sensor wiring between the sensor connector and the PCM. Note that there are splices in
the ground circuit.
NOTE: The quickest way to check the wiring is to measure the resistance of the thermistor at room temperature, connect
the sensor to the engine harness, and measure the resistance across PCM connector sockets CE1 and BE1. If the two
resistance values match, then the wiring is good.
DMT 2004 Digital Multimeter
Page 5A-20
c
16973
EGT Sensor Resistance Test
Temperature
0 °C (32 °F)
100 °C (212 °F)
© 2018 Mercury Marine
a - Pin A—ground (–)
b - Exhaust gas temperature sensor
c - Pin B—exhaust gas temperature signal (+)
8M0138392
91‑892647A01
Reading (nominal)
1,000 Ω
1,385 Ω
91‑892647A01
90-8M0146617 eng JULY 2018