Iat Sensor Test - Mercury V6 175 Diagnostic Manual

The IAT sensor is located in the starboard intake manifold, close to the fuel rail.
a - Starboard intake manifold, installed on engine (V8 shown, V6 similar)
b - Approximate location of IAT sensor
c - Starboard intake manifold, removed from engine (V8 shown, V6 similar)
d - IAT sensor

IAT Sensor Test

Monitor the intake air temperature (data item IAT) on the CDS G3 Live Data screen. With the engine cold and not running,
intake air temperature should be approximately the same as the ambient air temperature. After the engine is started, the
temperature sensor should indicate a rise in air intake temperature.
CDS G3 Interface Kit
If the IAT sensor does not indicate a temperature change, shake or move the harness. 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 connector from the IAT sensor.
2. Visually inspect the sensor pins and the wires coming from the engine harness connector. Look for broken, bent, or
corroded pins at the sensor and loose, broken, or corroded wires at the engine harness connector.
3. Test the sensor with an ohmmeter.
a. Remove the sensor from the intake manifold.
DMT 2004 Digital Multimeter
b. Immerse the sensor into a temperature controlled medium. If the readings do not match those in the table, replace the
sensor and retest.
a
90-8M0146617 eng JULY 2018
a - Pin A (signal)
b - Pin B (ground)
c - IAT sensor
c
b
17003
a
b
8M0138392
91‑892647A01
© 2018 Mercury Marine
c
d
67498
Sensors
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