1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 97Get this manual
ENGINE CONTROL SYSTEM 3-42
CHART3SELF-DIAGNOSTIC CODE "3-1"
Ignition switch "OFF"Check IAC valve resistanceIs result OK? (See page 3-35 YESIgnition switch "ON"Check "B4" terminal voltageIs result OK? (See page 3-33 YES Possible causeIncorrect by-pass air screw adjustment IAC valve failure (mechanical) IAC passage failure (clogged hosesilencer, etc ECM failure Wire continuityconnection failure NO ECM failure NO IAC valve failure
CHART4SELF-DIAGNOSTIC CODE "2-4"
Ignition switch "ON", crankingCheck CMP sensor signalIs result OK? (See page 3-38 YES Possible causeECM failure Wire continuityconnection failure NO CMP sensor failure