Engine Control System

DIAGNOSTIC CHART

Diagnostic Chart:

Diagnosis
Idle air control solenoid valve does not function.
Harness connector between ECM and solenoid valve is shorted or open.

Trouble Symptom
Engine stalls, poor idle quality, idle hunting.

CHECK INPUT SIGNAL FOR ECM

Input Signal:

1. Turn ignition ON.
2. Measure voltage between ECM and body.

Connector & Terminal Voltage
(E29) 2 - body 0V > 13V
(E29) 1 - body 13V > 0V


CHECK IDLE AIR CONTROL SOLENOID VALVE

Resistance Test:

1. Turn ignition OFF.
2. Unplug connector from idle air control solenoid valve.
3. Measure resistance between solenoid valve terminals.

Terminals Resistance
No. 1 - 2 32 ohms
No. 2 - 3 32 ohms

CHECK POWER SUPPLY TO IDLE AIR CONTROL SOLENOID VALVE

Power Supply Test:

1. Turn ignition ON.
2. Measure voltage between solenoid valve and body.

Connector & Terminal Voltage
(E11) 2 - body 10 V min.