Idle Air Control (Iac); Iac Removal - Mercury 25 EFI Service Manual

Service Procedures
13. Install the throttle body. Refer to Section 3C ‑ Throttle Body.
14. Install the engine harness. Refer to Section 2B ‑ Engine Wire Harness.
15. Install the ECM. Refer to Section 2A ‑ Ignition Components.
16. Install the voltage regulator. Refer to Section 2B ‑ Battery Charging System.

Idle Air Control (IAC)

The Idle Air Control (IAC) is an electrically operated spring‑loaded solenoid valve which controls the amount of air bypassing
the closed throttle shutter. Signals from the ECM regulate the duty cycle that the IAC valve remains open or closed. The duty
cycle ranges from 0% to 100% open.

IAC Removal

NOTE: Refer to Section 2B ‑ Engine Wire Harness to remove the engine wire harness.
1. Remove the green and blue trim motor wires from the down and up solenoids.
a
2. Remove the nut securing the two ground wires to the trim up solenoid. Remove the ground wires from the trim up solenoid.
3. Remove the bolt securing the two solenoid ground wires and the starter relay ground wire.
4. Remove the bolt securing the support bracket to the electrical bracket.
a
Page 3C-48
b
20837
c
© 2016 Mercury Marine
a - Green trim motor wire
b - Blue trim motor wire
a - Nut securing the two ground wires
b
b - Bolt securing the two solenoid ground
wires, and the starter relay ground wire
c - Bolt securing the support bracket
20897
90-8M0105568 eng MARCH 2016