RM38T0EC _51 Engine / Hybrid System _115233 STOP AND START _0510781 STOP AND START SYSTEM J

STOP AND START  STOP AND START SYSTEM  Starter Inrush Current Reduction Relay Circuit  


DESCRIPTION

The starter inrush current reduction relay prevents the auxiliary battery voltage from becoming dropping excessively while the starter assembly is operating. If the auxiliary battery voltage drops below the threshold, stop and start control will be prohibited. In order to prevent this, the engine stop and start ECU operates the starter inrush current reduction relay for approximately 0.1 seconds after the ST relay is activated. By allowing current to flow to the starter inrush current reduction relay, the current that flows to the starter motor is reduced, preventing the auxiliary battery voltage from dropping excessively.

A434152E02
0.167,0.969 1.823,1.302 1.656,0.333 10 false from Auxiliary Battery 0.604,2.646 1.979,2.969 1.375,0.323 10 false from ST Relay 2.469,0.875 2.813,1.104 0.344,0.229 10 false B 2.448,2.531 2.896,2.813 0.448,0.281 10 false ST 0.146,0.094 1.781,0.385 1.635,0.292 10 false Starter Assembly 4.167,1.698 6.563,1.917 2.396,0.219 10 false Starter Inrush Current Reduction Relay

CAUTION / NOTICE / HINT

HINT:
·

Starter inrush current reduction relay stuck on:

When the engine is started by stop and start control, a large amount of current will flow to the starter assembly, the auxiliary battery voltage will drop excessively and stop and start control will be canceled.

·

Starter inrush current reduction relay stuck off:

Operating current will always flow through the starter inrush current reduction relay and the cranking speed will be low.



PROCEDURE

1.CHECK WAVEFORM (STARTER INRUSH CURRENT REDUCTION RELAY)
a.

Connect the positive (+) lead of an oscilloscope to the positive (+) auxiliary battery terminal and the negative (-) lead to the negative (-) auxiliary battery terminal.


b.

While cranking the engine, count the number of times the waveform drops.

A285238E13
2.719,0.448 3,0.167 3,0.167 3.333,0.167 false 0.104,0.208 0.813,0.406 0.708,0.198 10 false Normal: 0.146,1.469 0.823,1.667 0.677,0.198 10 false Abnormal: 0.146,2.417 0.854,2.615 0.708,0.198 10 false Abnormal: 1.135,0.896 2.281,1.188 1.146,0.292 10 false 7.6 to 9.3 V* 0.094,0.552 1.021,0.896 0.927,0.344 10 false Approximately 12 V 3.396,0.073 5.469,0.281 2.073,0.208 10 false Approximately 0.1 seconds 2.573,1.344 4.125,1.542 1.552,0.198 10 false Less than 3 seconds 4.667,1.854 6.656,2.052 1.99,0.198 10 false : Voltage drops only 1 time 4.635,2.708 7.073,2.917 2.438,0.208 10 false : Voltage drops excessively only 1 time 4.25,3.438 6.979,3.646 2.729,0.208 10 false *: Varies with auxiliary battery condition 0.146,1.813 1.073,2.156 0.927,0.344 10 false Approximately 12 V 0.146,2.719 1.073,3.063 0.927,0.344 10 false Approximately 12 V

Standard:

Waveform drops 2 times



Result:
Proceed to
OK
NG



OK

NG