ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE) 6-2-135
Troubleshooting
Step Action Yes No
1Was “Engine and Emission Control System
Check” performed?
Go to Step 2. Go to “Engine and Emis-
sion Control System
Check” in this section.
2 Idle Speed Check
1) Check idle speed/idle air control duty refer-
ring to “Idle Speed/Idle Air Control Duty
Inspection” in Section 6E1.
Is check result as specified?
Go to Step 3. Go to Step 4.
3 Idle Air Control Valve Operation Check
1) Check idle air control valve for operation
referring to “Idle Air Control (IAC) Valve
Operation Check” in this section.
Is check result satisfactory?
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection” in Section 0A.
If OK, substitute a known-
good ECM and recheck.
Go to Step 4.
4 Idle Air Control Valve Circuit Check
1) Disconnect connector from idle air control
valve with ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage
between “BLK/RED” wire terminals of idle
air control valve connector and engine
ground.
Is voltage 10 – 14 V?
Go to Step 5. “BLK/RED” wire in open
or high resistance circuit.
5 Idle Air Control Valve Check
1) Check idle air control valve for resistance
referring to “Idle Air Control (IAC) Valve
Check” in this section.
Is check result satisfactory?
Go to Step 6. Replace idle air control
valve.
6 Idle Air Control Valve Circuit Check
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Measure resistance between “BLK/RED”
wire terminal of idle air control valve con-
nector and “E23-8” terminal of ECM con-
nector.
Are resistance 2
Ω
or less?
Go to Step 7. “BLK/RED” or “GRN/YEL”
wire in open or high resis-
tance circuit.
7 Idle Air Control Valve Circuit Check
1) Measure resistance between “E23-8” termi-
nal of ECM connector and vehicle body
ground.
Is resistance infinite?
Go to Step 8. “BLK/RED” or “GRN/REL”
wire in shorted to ground
circuit.
8 Idle Air Control Valve Circuit Check
1) Connect connectors to ECM.
2) Turn ON ignition switch, measure voltage
between “E23-8” terminal of ECM connector
and vehicle body ground.
Is each voltage 0 V?
Replace idle air control
valve.
“BLK/RED” or “GRN/YEL”
wire in shorted to power
circuit.