58073

Description

First of all check damage of terminals : Check terminals for contact resistance, corrosion and deformation.

When battery power is NOT supplied to ECM although main relay circuit is normal.

Inspect coil and contacts in the main relay (Engine control relay).

Diagnostic Procedure

Main relay coil resistance inspection

IG KEY "OFF", ENGINE "OFF"

After approx. 10 seconds later disconnect a main relay.

Before measuring resistance, you must calibrate(0Ω) the tester.

note

Refer to "Multimeter calibration inspection" of detail inspections (Equipment settings).

Measuring the resistance between main rely component terminal "85" and "86".

■ Specification : 75Ω ± 10% ( 20℃ )

Main relay contacts inspection

Measuring the resistance between main rely component terminal "30" and "87".

■ Specification : Discontinuity (Infinite Ω)

Measuring the resistance between main rely component terminal "87" and "87".

■ Specification : Continuity (below 1.0Ω)

Actuate the main relay after supplying power and ground to main relay component terminal "85" and "86".

Inspect operating sound in the main relay when power is supplied.

Measure the resistance between main rely component terminal "30" and "87".(Actuate main relay after supplying power and ground to main relay component terminal "85" and "86".)

■ Specification : Continuity (below 1.0Ω)

Main relay visual inspection

※ If trouble symptom occurs intermittently although relay is operated well as above, Inspect the inside of the relay.

☞ Make sure of damage of the relay cover.

- Contact : Inspect contact connection and carbon deposit by spark.

- Coil : Inspect partial damage by coil short and enamel coating damage.

Symptom		Inspection procedure
Case1	● High resistance of the main relay coil (Open)	● In case that main relay is not operated by high resistance (open) of the relay coil. ☞ Replace the main relay.
Case2	● Low resistance of the main relay coil (Short)	● In case that main relay is not operated by low resistance (short) of the relay coil. ☞ Replace the main relay.
Case3	● Intermittent poor connection between contacts. (Main relay coil is normal.)	● In case of intermittent poor connection, ☞ Replace the main relay.